Tài liệu hạn chế xem trước, để xem đầy đủ mời bạn chọn Tải xuống
1
/ 97 trang
THÔNG TIN TÀI LIỆU
Thông tin cơ bản
Định dạng
Số trang
97
Dung lượng
7,08 MB
Nội dung
PHẦN 1: CƠ HỌC A particle moves according to the equation x =10t2 where x is in meters and t is in seconds (a) Find the average velocity for the time interval from 2.00 s to 3.00 s.(b) Find the average velocity for the time interval from2.00 s to 2.10 s Ans (a) 50m/s (b) 41m/s A 50.0-g Super Ball traveling at 25.0 m/s bounces off abrick wall and rebounds at 22.0 m/s A high-speed camera records this event If the ball is in contact with the wall for 3.50 ms, what is the magnitude of the average acceleration of the ball during this time interval? Ans 1.34x104m/s2 A jet plane comes in for a landing with a speed of 100 m/s, and its acceleration can have a maximum magnitude of 5.00 m/s2as it comes to rest (a) From the instant the plane touches the runway, what is the minimum time interval needed before it can come to rest? (b) Can this plane land on a small tropical island airport where the runway is 0.800 km long? Explain your answer Ans (a) 20s A particle moves along the x axis Its position is given by the equation x = + 3t - 4t2, with x in meters and t in seconds Determine (a) its position when it changes direction and (b) its velocity when it returns to the position it had at t = Ans (a) Figure 2.56m (b) -3m/s An electron in a cathode-ray tube accelerates from a speed of 2.00 x104 m/s to 6.00 x106 m/s over 1.50 cm (a) In what time interval does the electron travel this 1.50 cm? (b) What is its acceleration? Ans (a) 4.98x10-9s (b) 1.2x1015m/s2 A firefighter, a distance d from a burning building, directs a stream of water from a fire hose at angle i above the horizontal as shown in Figure If the initial speed of the stream is vi, at what height h does the water strike the building? In Fig 2, a stone is projected at a cliff of height h with an initial speed of 42.0 m/s directed at angle 0 = 60.0° above the horizontal The stone strikes at A, 5.50 s after cliff, (b) the speed (c) the maximum A soccer player high cliff into a sound of the splash given to the rock? m/s Ans 9.91m/s Figure launching Find (a) the height h of the of the stone just before impact at A, and height H reached above the ground kicks a rock horizontally off a 40.0-mpool of water If the player hears the 3.00 s later, what was the initial speed Assume the speed of sound in air is 343 A train slows down as it rounds a sharp horizontal turn,slowing from 90.0 km/h to 50.0 km/h in the 15.0 s that it takes to round the bend The radius of the curve is 150 m Compute the acceleration at the moment the train speed reaches 50.0 km/h Assume it continues to slow down at this time at the same rate Ans 1.48m/s2 10 A person standing at the top of a hemispherical rock of radius R kicks a ball (initially at rest on the top of the rock) to give it horizontal velocity as shown in Figure (a) What must be its minimum initial speed if the ball is never to hit the rock after it is kicked? (b) With this initial speed, how far from the base of the rock does the ball hit the ground? Ans (a) vi gR (b) ( 1)R 11 A car travels due east with a speed of 50.0 km/h Rain- Figure drops are falling at a constant speed vertically with respect to the Earth The traces of the rain on the side windows of the car make an angle of 60.0° with the vertical Find the velocity of the rain with respect to (a) the car and (b) the Earth Ans (a) 57.7km/h (b) 28.9km/h 12 A light string can support a stationary hanging load of 25.0 kg before breaking A 3.00-kg object attached to the string rotates on a horizontal, frictionless table in a circle of radius 0.800 m, and the other end of the string is held fixed What range of speeds can the object have before the string breaks? Ans v 8.08m / s 13 A 4.00-kg object is attached to a vertical rod by two strings as shown in Figure The object rotates in a horizontal circle at constant speed 6.00 m/s Find the tension in (a) the upper string and (b) the lower string Ans Ta =108N; Tb=56.2N 14 Two balls with masses M and m are connected by a rigid rod of length L and negligible mass as shown in Figure For an axis perpendicular to the rod, show that the system has the minimum moment of inertia when the axis passes through the center of mass Show that this moment of Figure inertia is I =L2, where = mM/(m + M) 15 A uniform, thin solid door has height 2.20 m, width 0.870 m, and mass 23.0 kg Find its moment of inertia for rotation on its hinges Is any piece of data unnecessary? Ans 5.8kgm2 Figure 16 The combination of an applied force and a friction force produces a constant total torque of 36.0 Nm on a wheel rotating about a fixed axis The applied force acts for 6.00 s During this time, the angular speed of the wheel increases from to 10.0 rad/s The applied force is then removed, and the wheel comes to rest in 60.0 s Find (a) the moment of inertia of the wheel, (b) the magnitude of the frictional torque, and (c) the total number of revolutions of the wheel Ans (a) 21.6 kgm2 (b) 3.6 Nm (c) 52.4 rev 17 A block of mass m1 = 2.00 kg and a block of mass m2 = 6.00 kg are connected by a massless string over a pulley in the shape of a solid disk having radius R = 0.250 m and mass M = 10.0 kg These blocks are allowed to move on a fixed wedge of angle =30.0° as shown in Figure 6.The coefficient of kinetic friction is 0.360 for both blocks Draw free-body diagrams of both blocks and of the pulley Determine (a) the acceleration of the two blocks and (b) the tensions in the Figure string on both sides of the pulley Ans 0.309m/s2, 7.67N, 9.22N 18 Consider the system shown in Figure with m1=20.0 kg, m2 =12.5 kg, R = 0.200 m, and the pulley is a uniform solid disk mass M = 5.00 kg Object m2 is resting on the floor, and object m1 is 4.00 m above the floor when it is released from rest The pulley axis is frictionless The cord is light, does not stretch, and does not slip on the pulley Calculate the time interval required for m1 to hit the floor How would your answer change if the pulley were massless? Ans 2.27s, 1.56s 19 (a) A uniform solid disk of radius R and mass M is free to rotate on a frictionless pivot through a point on its rim (Fig 8) If the disk is released from Figure rest in the position shown by the blue circle, what is the speed of its center of mass when the disk reaches the position indicated by the dashed circle? (b) What is the speed of the lowest point on the disk in the dashed position? (c) Repeat part (a) using a uniform hoop Ans (a) gR / (b) gR / (c) gR 20 A cylinder of mass 10.0 kg rolls without slipping on a horizontal surface At a certain instant its center of mass has a speed of 10.0 m/s Figure Determine (a) the translational kinetic energy of its center of mass, (b) the rotational kinetic energy about its center of mass, and (c) its total energy Ans (a) 500J (b) 250J (c) 750J 21 A solid sphere is released from height h from the top of an incline making an angle with the horizontal Calculate the speed of the sphere when it reaches the bottom of the incline (a) in the case that it rolls without slipping and (b) in the case that it slides frictionlessly without rolling (c) Compare the time intervals required to reach the bottom in cases (a) and (b) Ans (a) 10 gh / (b) 2gh 22 A uniform solid disk and a uniform hoop are placed side by side at the top of an incline of heighth If they are released from rest at the same time and roll without slip-ping, which object reaches the bottom first? Verify your answer by calculating their speeds when they reach the bottom in terms of h Ans the disk reaches the bottom first 23 The reel shown in Figure has radius R and moment of inertia I One end of the block of mass m is connected to a spring of force constant k, and the other end is fastened to a cord wrapped around the reel The reel axle and Figure the incline are frictionless The reel iswound counterclockwise so that the spring stretches a dis-tance d from its unstretched position and the reel is then released from rest (a) Find the angular speed of the reel when the spring is again unstretched (b) Evaluate the angular speed numerically at this point, taking I=1.00 kg m2, R = 0.300 m, k = 50.0 N/m, m = 0.500 kg, d = 0.200 m, and =37.0° Ans 1.74rad/s 24 A uniform solid sphere of radius r is placed on the inside surface of a hemispherical bowl with much larger radius R The sphere is released from rest at an angle to the vertical and rolls without slipping (Fig 10) Figure 10 Determine the angular speed of the sphere when it reaches the bottom of the bowl Ans 10 ( R r )(1 cos ) g r2 25 A solid sphere of mass m and radius r rolls without slipping along the track shown in Figure 11 It starts from rest with the lowest point of the sphere at height h above the bottom of the loop of radius R, much larger than r (a) What is the minimum value of h (in terms of R) such that the sphere completes the loop? (b) What are the components of the net force on the sphere at the point P if h = 3R ? Ans (a) hmin=2.7R, (b) Fx=20mg/7; Fy = -5mg/7 26 The system shown in Figure 12 consists of a light, inextensible cord; light, frictionless pulleys; and blocks of equal mass It is initially held at rest so that the blocks are at the same height above the ground The blocks are then released Find the speed of block A at the moment when the vertical separation of the blocks is h Ans vA Figure 11 Figure 12 gh 15 27 A pendulum, comprising a light string of length L and a small sphere, swings in the vertical plane The string hits a peg located a distance d below the point of suspension (Fig 13) (a) Show that if the sphere is released from a Figure 13 height below that of the peg, it will return to this height after the string strikes the peg (b) Show that if the pen-dulum is released from the horizontal position ( =90°) and is to swing in a complete circle centered on the peg, the minimum value of d must be 3L/5 28 Two blocks are free to slide along the frictionless wooden track ABC shown in Figure 14 The block of mass m1 =5.00 kg is released from A Protruding from its front end is the north pole of a strong magnet, which is repelling the north pole of an identical magnet embedded in the back end of the block of mass m2 10.0 kg, initially at rest The two blocks never touch Figure 14 Calculate the maximum height to which m1 rises after the elastic collision Ans 0.556m 29 A 5.00g bullet moving with an initial speed of 400 m/s is fired into and passes through a 1.00-kg block as shown in Figure 15 The block, initially at rest on a frictionless, horizontal surface, is connected to a spring with force constant 900 N/m The block moves 5.00 cm to the right after impact Find (a) the speed at which the bullet emerges from the block and (b) the mechanical energy converted into internal energy in the collision Ans (a) 100m/s (b) 374J Figure 15 30 A particle of mass m is shot with an initial velocity vi making an angle with the horizontal The particle moves in the gravitational field of the Earth Find the angular momentum of the particle about the origin when the particle is (a) at the origin, (b) at thebhighest point of its trajectory, and (c) just before it hits the ground (d) What torque causes its angular momentum to change? 31 A conical pendulum consists of a bob of mass m in motion in a circular path in a horizontal plane as shown in Figure 16 During the motion, the supporting wire of length l maintains the constant angle with the vertical Show that the magnitude of the angular momentum of the bob about the circle’s center is: m2 gl sin L cos 32 A uniform solid sphere of radius 0.500 m and mass 15.0 kg turns Figure 16 counterclockwise about a vertical axis through its center Find its vector angular momentum when its angular speed is 3.00 rad/s Ans 4.5kgm2/s 33 A uniform solid disk of mass 3.00 kg and radius 0.200 m rotates about a fixed axis perpendicular to its face with angular frequency 6.00 rad/s Calculate the angular mo-mentum of the disk when the axis of rotation (a) passes through its center of mass and (b) passes through a point midway between the center and the rim Ans (a) 0.36 kgm2/s (b) 0.54 kgm2/s 34 A particle of mass 0.400 kg is attached to the 100-cm mark of a meterstick of mass 0.100 kg The meterstick rotates on a horizontal, frictionless table with an angular speed of 4.00 rad/s Calculate the angular momentum of the system when the meterstick is pivoted about an axis (a) perpendicular to the table through the 50.0-cm mark and (b) perpendicular to the table through the 0-cm mark Ans (a) 0.433 kgm2/s (b) 1.73 kgm2/s 35 A uniform cylindrical turntable of radius 1.90 m and mass 30.0 kg rotates counterclockwise in a horizontal plane with an initial angular speed of 4 rad/s The fixed turntable bearing is frictionless A lump of clay of mass 2.25 kg and negligible size is dropped onto the turntable from a small distance above it and immediately sticks to the turntable at a point 1.80 m to the east of the axis (a) Find the final angular speed of the clay and turntable (b) Is mechanical energy of the turntable-clay system conserved in this process? Explain and use numerical results to verify your answer (c) Is momentum of the system conserved in this process? Explain your answer 36 A uniform rod of mass 300 g and length 50.0 cm rotates in a horizontal plane about a fixed, vertical, frictionless pin through its center Two small, dense beads, each of mass m, are mounted on the rod so that they can slide without friction along its length Initially, the beads are held by catches at positions 10.0 cm on each side of the center, and the system is rotating at an angular speed of 36.0 rad/s The catches are released simultaneously, and the beads slide outward along the rod Find the angular speed of the system at the instant the beads slide off the ends of the rod as it depends on m Ans 9.2rad/s 37 A wad of sticky clay with mass m and velocity is fired at a solid cylinder of mass M and radius R (Figure 17) The cylinder is initially at rest and is mounted on a fixed horizontal axle that runs through its center of mass The line of motion of the projectile is perpendicu-lar to the axle and at a Figure 17 distance d< R from the center (a) Find the angular speed of the system just after the clay strikes and sticks to the surface of the cylinder (b) Is mechanical energy of the clay-cylinder system conserved in this process? Explain your answer (c) Is momentum of the clay-cylinder system conserved in this process? Explain your answer Ans 2mvi d ( M 2m) R 38 A wooden block of mass M resting on a frictionless, horizontal surface is attached to a rigid rod of length l and of negligible mass (Fig 18) The rod is pivoted at the other end A bullet of mass m traveling parallel to the horizontal surface and perpendicular to the rod with speed v hits the block and becomes embedded in it (a) What is the Figure 18 angular momentum of the bullet–block system? (b) What fraction of the original kinetic energy is converted into internal energy in the collision? Ans (a) mvl (b) M/(M+m) 39 A projectile of mass m moves to the right with a speed vi (Fig P19a) The projectile strikes and sticks to the end of a stationary rod of mass M, length d, pivoted about a frictionless axle through its center (Fig P19b) (a) Find the angular speed of the system right after the collision (b) Determine the fractional loss in mechanical energy due to the collision Ans (a) Figure 19 6mvi M (b) M 3m ( M 3m)d 40 A 2.0-kg disk traveling at 3.0 m/s strikes a 1.0-kg stick of length 4.0 m that is lying flat on nearly frictionless ice as shown in the overhead view of Figure 20a Assume the collision is elastic and the disk does not deviate from its original line of motion Find the translational speed of the disk, the translational speed of the stick, and the angular speed of the stick after the collision The moment of inertia of the stick about its center of mass is 1.33 kgm2 Ans vd = 2.3 m/s, vs= 1.3 m/s, and =2.0 rad/s 41 Two objects are connected by a light string passing over a light, Figure 20 frictionless pulley as shown in Figure P8.7 The object of mass 5.00 kg is released from rest Using the iso-lated system model, (a) determine the speed of the 3.00-kg object just as the 5.00-kg object hits the ground (b) Find the maximum height to which the 3.00-kg object rises Ans: 4.43m/s; 5m 42 The coefficient of friction between the 3.00-kg block and the surface in Figure P8.19 is 0.400 The system starts from rest What is the speed of the 5.00-kg ball when it has fallen 1.50 m? Ans 3.74m/s 43 A 5.00-kg block is set into motion up an inclined plane with an initial speed of 8.00 m/s (Fig P8.21) The block comes to rest after traveling 3.00 m along the plane, which is inclined at an angle of 30.0° to the horizontal For this motion, determine (a) the change in the block’s kinetic energy, (b) the change in the potential energy of the block–Earth system, and (c) the friction force exerted on the block (assumed to be constant) (d) What is the coefficient of kinetic friction? Ans (a) -160J (b) 73.5J (c) 28.8N (d) 0.679 44 An 80.0-kg skydiver jumps out of a balloon at an alti-tude of 000 m and opens the parachute at an altitude of 200 m (a) Assuming the total retarding force on the diver is constant at 50.0 N with the parachute closed and con-stant at 600 N with the parachute open, find the sky-diver’s speed when he lands on the ground (b) Do you think the skydiver will be injured? Explain (c) At what height should the parachute be opened so that the final speed of the skydiver when he hits the ground is 5.00 m/s? (d) How realistic is the assumption that the total retarding force is constant? Explain Ans (a) 24.5m/s (c) 206m 45 A toy cannon uses a spring to project a 5.30-g soft rubber ball The spring is originally compressed by 5.00 cm and has a force constant of 8.00 N/m When the cannon is fired, the ball moves 15.0 cm through the horizontal bar-rel of the cannon and the barrel exerts a constant friction force of 0.032 N on the ball (a) With what speed does the projectile leave the barrel of the cannon? (b) At what point does the ball have maximum speed? (c) What is this maximum speed? Ans (a) 1.4m/s (b) 4.6 cm from the start (c) 1.79m/s 46 A 3.00-kg steel ball strikes a wall with a speed of 10.0 m/s at an angle of 60.0° with the surface It bounces off with the same speed and angle (Fig P9.9) If the ball is in contact with the wall for 0.200 s, what is the average force exerted by the wall on the ball? Ans -260N 47 A bullet of mass m is fired into a block of mass M initially at rest at the edge of a frictionless table of height h (Fig.P9.57) The bullet remains in the block, and after impact the block lands a distance d from the bottom of the table Determine the initial speed of the M m gd m 2h bullet Ans 48 A small block of mass m1 = 0.500 kg is released from rest at the top of a curve-shaped, frictionless wedge of mass m2 = 3.00 kg, which sits on a frictionless horizontal surface as shown in Figure P9.58a When the block leaves the wedge, its velocity is measured to be 4.00 m/s to the right as shown in the figure (a) What is the velocity of the wedge after the block reaches the horizontal surface? (b) What is the height h of the wedge? Ans (a) - 0.667m/s (b) 0.952m 49 Rigid rods of negligible mass lying along the y axis connect three particles (Fig P10.22) The system rotates about the x axis with an angular speed of 2.00 rad/s Find (a) the moment of inertia about the x axis and the total rotational kinetic energy evaluated from and (b) the tangential speed of each particle and the total kinetic energy evaluated from (c) Compare the answers for kinetic energy in parts (a) and (b) Ans (a) 92kg.m2; 184J (b) v1 = 6m/s; v2 = 4m/s; v3 = 8m/s; 184J 50 A uniform, thin solid door has height 2.20 m, width 0.870 m, and mass 23.0 kg Find its moment of inertia for rotation on its hinges Is any piece of data unnecessary? Ans 5.8kg.m2 51 Find the net torque on the wheel in Figure P10.33 about the axle through O, taking a = 10.0 cm and b =25.0 cm Ans 3.55 Nm 52 A potter’s wheel—a thick stone disk of radius 0.500 m and mass 100 kg—is freely rotating at 50.0 rev/min The pot-ter can stop the wheel in 6.00 s by pressing a wet rag against the rim and exerting a radially inward force of 70.0 N Find the effective coefficient of kinetic friction between wheel and rag Ans 0.312 53 Big Ben, the Parliament tower clock in London, has an hour hand 2.70 m long with a mass of 60.0 kg and a minute hand 4.50 m long with a mass of 100 kg Calculate the total rotational kinetic energy of the two hands about the axis of rotation (You may model the hands as long, thin rods.) Ans 1.04x10-3J 54 The top in Figure P10.43 has a moment of inertia equal to 4.00x10-4 kg.m2 and is initially at rest It is free to rotate about the stationary axis AA’ A string, wrapped around a peg along the axis of the top, is pulled in such a manner as to maintain a constant tension of 5.57 N If the string does not slip while it is unwound from the peg, what is the angular speed of the top after 80.0 cm of string has been pulled off the peg? Ans 149 rad/s 55 In Figure P10.45, the sliding block has a mass of 0.850 kg, the counterweight has a mass of 0.420 kg, and the pulley is a hollow cylinder with a mass of 0.350 kg, an inner radius of 0.020 m, and an outer radius of 0.030 m The coefficient of kinetic friction between the block and the horizontal surface is 0.250 The pulley turns without friction on its axle The light cord does not stretch and does not slip on the pulley The block has a velocity of 0.820 m/s toward the pulley when it passes through a photogate (a) Use energy methods to predict its speed after it has moved to a second photogate, 0.700 m away (b) Find the angular speed of the pulley at the same moment Ans (a) 1.59m/s (b) 53.1 rad/s 56 A cylindrical rod 24.0 cm long with mass 1.20 kg and radius 1.50 cm has a ball of diameter 8.00 cm and mass 2.00 kg attached to one end The arrangement is origi-nally vertical and stationary, with the ball at the top The system is free to pivot about the bottom end of the rod after being given a slight nudge (a) After the rod rotates through 90°, what is its rotational kinetic energy? (b) What is the angular speed of the rod and ball? (c) What is the linear speed of the ball? (d) How does this speed compare with the speed if the ball had fallen freely through the same distance of 28 cm? Ans (a) 6.9J (b) 8.73rad/s (c) 2.44m/s (d) 1.043 times 57 This problem describes one experimental method for determining the moment of inertia of an irregularly shaped object such as the payload for a satellite Figure P10.49 shows a counterweight of mass m suspended by a cord wound around a spool of radius r, forming part of a turntable supporting the object The turntable can rotate without friction When the counterweight is released from rest, it descends through a distance h, acquiring a speed v Show that the moment of inertia I of the rotating appa-ratus (including the turntable) is mr2(2gh/v2-1) 58 A uniform, hollow, cylindrical spool has inside radius R/2, outside radius R, and mass M (Fig P10.69) It is mounte so that it rotates on a fixed, horizontal axle A counter-weight of mass m is connected to the end of a string wound around the spool The counterweight falls from rest at t = to a position y at time t Show that the torque due to the friction forces between spool and axle is: 59 A uniform solid sphere of radius 0.500 m and mass 15.0 kg turns counterclockwise about a vertical axis through its center Find its vector angular momentum when its angular speed is 3.00 rad/s Ans 4.5 kgm2/s 60 A uniform solid disk of mass 3.00 kg and radius 0.200 m rotates about a fixed axis perpendicular to its face with angular frequency 6.00 rad/s Calculate the angular mo-mentum of the disk when the axis of rotation (a) passes through its center of mass and (b) passes through a point midway between the center and the rim Ans (a) 0.36 kgm2/s (b) 0.54 kgm2/s 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 Đề TT Giải Đề TT Giải Đề TT b b b ài ài ài Giải 2.4 P2.4 2.10 P2.11 2.23 2.28 P2.25 2.29 2.33 4.14 4.20 4.28CSVL 4.21 4.23 4.29 4.33 10 4.54 4.62 11 4.33 4.39 12 6.1 6.1 13 6.11 6.11 14 10.23 10.22 15 10.28 10.25 16 10.36 10.36 17 10.37 10.37 18 10.44 19 10.51 10.49 20 10.53 10.51 21 10.52 22 10.56 10.54 23 10.72 10.70 24 10.78 10.76 25 10.79 10.79 26 8.12 8.20 27 8.62 8.72 28 9.19 9.20 29 9.67 9.67 30 11.17 11.17 31 11.14 11.14 32 11.22 11.22 33 11.23 11.23 34 11.25 11.25 35 11.31 36 11.34 11.31 37 11.39 11.37 38 11.37 11.35 39 11.50 11.50 40 Ex 11.9 41 8.7 8.13 42 8.19 8.31 43 8.21 8.33 44 8.22 8.34 45 8.23 8.35 47 9.57 9.58 48 9.57 9.60 49 10.22 10.20 50 10.28 10.25 51 10.33 10.31 52 10.38 10.38 53 10.42 10.40 54 10.43 10.42 55 10.45 10.43 56 10.46 10.44 57 10.49 10.47 58 10.69 10.69 59 11.22 11.22 60 11.23 11.23 61 19.18 19.26 62 19 29 63 20 31 64 21 33 65 25 37 66 27 39 67 28 42 68 38 50 69 39 53 70 54 68 71 20.21 20.23 72 23 25 73 24 26 74 25 27 75 26 30 76 27 39 77 28 32 78 30 34 79 31 35 80 34 38 81 35 39 82 VD21.2 83 21.13 21.15 84 14 16 85 16 18 86 18 24 87 19 25 88 20 26 89 23 29 90 25 31 91 40 50 92 44 54 93 22.10 22.10 94 11 95 12 12 96 13 13 97 27 31 98 39 45 99 40 46 100 49 57 101 54 62 102 55 65 103 59 69 104 23.5 23.5 105 6 106 7 107 10 108 17 109 20 26 110 21 25 111 27 33 112 29 35 113 30 36 114 42 50 115 43 51 116 45 55 117 47 57 118 49 59 119 51 61 120 53 63 121 56 68 122 55 65 123 24.15 24.19 124 16 20 125 18 24 126 22 26 127 26 28 128 27 29 129 29 31 130 28 32 131 33 39 132 34 42 133 35 43 134 43 53 135 47 57 136 50 62 137 52 64 138 55 67 139 56 68 140 57 69 141 58 70 142 VD25.5 143 VD 25.6 144 VD25.7 145 25.12 25.18 146 30 38 147 31 39 148 34 42 149 35 43 150 38 47 151 39 49 152 40 48 153 59 67 154 60 68 155 62 72 156 63 71 157 29.29 29.15 158 35 23 159 34 22 160 46 54 161 30.3 30.3 162 163 5 164 10 165 10 10 166 14 14 167 15 15 168 18 16 169 19 170 23 21 171 31.20 31 174 49 32.3 177 180 Giải TT 172 29 173 175 60 176 178 179 TT Đề Giải TT 32.1 Đề 2 Đề b b b ài ài ài Giải 2.4 P2.4 2.10 P2.11 2.23 2.28 P2.25 2.29 2.33 4.14 4.20 4.28CSVL 4.21 4.23 4.29 4.33 10 4.54 4.62 11 4.33 4.39 12 6.1 6.1 13 6.11 6.11 14 10.23 10.22 15 10.28 10.25 16 10.36 10.36 17 10.37 10.37 18 10.44 19 10.51 10.49 20 10.53 10.51 21 10.52 22 10.56 10.54 23 10.72 10.70 24 10.78 10.76 25 10.79 10.79 26 8.12 8.20 27 8.62 8.72 28 9.19 9.20 29 9.67 9.67 30 11.17 11.17 31 11.14 11.14 32 11.22 11.22 33 11.23 11.23 34 11.25 11.25 35 11.31 36 11.34 11.31 37 11.39 11.37 38 11.37 11.35 39 11.50 11.50 40 Ex 11.9 41 8.7 8.13 42 8.19 8.31 43 8.21 8.33 44 8.22 8.34 45 8.23 8.35 47 9.57 9.58 48 9.57 9.60 49 10.22 10.20 50 10.28 10.25 51 10.33 10.31 52 10.38 10.38 53 10.42 10.40 54 10.43 10.42 55 10.45 10.43 56 10.46 10.44 57 10.49 10.47 58 10.69 10.69 59 11.22 11.22 60 11.23 11.23 61 19.18 19.26 62 19 29 63 20 31 64 21 33 65 25 37 66 27 39 67 28 42 68 38 50 69 39 53 70 54 68 71 20.21 20.23 72 23 25 73 24 26 74 25 27 75 26 30 76 27 39 77 28 32 78 30 34 79 31 35 80 34 38 81 35 39 82 VD21.2 83 21.13 21.15 84 14 16 85 16 18 86 18 24 87 19 25 88 20 26 89 23 29 90 25 31 91 40 50 92 44 54 93 22.10 22.10 94 11 95 12 12 96 13 13 97 27 31 98 39 45 99 40 46 100 49 57 101 54 62 102 55 65 103 59 69 104 23.5 23.5 105 6 106 7 107 10 108 17 109 20 26 110 21 25 111 27 33 112 29 35 113 30 36 114 42 50 115 43 51 116 45 55 117 47 57 118 49 59 119 51 61 120 53 63 121 56 68 122 55 65 123 24.15 24.19 124 16 20 125 18 24 126 22 26 127 26 28 128 27 29 129 29 31 130 28 32 131 33 39 132 34 42 133 35 43 134 43 53 135 47 57 136 50 62 137 52 64 138 55 67 139 56 68 140 57 69 141 58 70 142 VD25.5 143 VD 25.6 144 VD25.7 145 25.12 25.18 146 30 38 147 31 39 148 34 42 149 35 43 150 38 47 151 39 49 152 40 48 153 59 67 154 60 68 155 62 72 156 63 71 157 29.29 29.15 158 35 23 159 34 22 160 46 54 161 30.3 30.3 162 163 5 164 10 165 10 10 166 14 14 167 15 15 168 18 16 169 19 170 23 21 171 31.20 31 174 49 32.3 177 180 172 29 173 175 60 176 179 178 32.1 2 ... 10 0V 17 7 Ans 10 0V 17 9 Ans -0.421A/s 17 8 Ans 6cos (12 0t) V 18 0 Ans (a) 360mV (b) 18 0mV (c) 3s SOLUTION 5 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34... (c) E =11 .9MV/m ; V= 1. 67MV 15 2 Ans 1. 56x1 012 e 15 3 14 7 Ans 7.07 V/m 14 8 Ans V2R-VO=-0.553kQ/R 14 9 Ans 15 4 Ans 15 0 Ans VO = k(+2ln3) kQ 15 5 Ans W R 15 6 Ans PHẦN TỪ TRƯỜNG 15 7 Ans 1. 07 m/s 16 0... 10 .9nC (b) 5.44x10-3N 11 7 Ans 40.9 N 11 9 11 8 Ans L k ( L Li ) ke 12 0 Ans 0.707 N 12 4 Ans 28.2Nm2/C 12 1 Ans 12 5 Ans (a) (b) 365kV/m (c) 1. 46MV/m (d) 649 kV/m 12 6 Ans (a) 913 nC (b) 12 2 Ans ? ?1=