Chúc bạn học tốtBài 1. Một người lái một chiếc xe ô tô xuất phát từ A lúc giờ, chuyển động thẳng đều đến B, cách A là . a Tính vận tốc của xe, biết rằng xe đến B lúc giờ phút ? b Sau phút đỗ tại B, xe chạy ngược về A với vận tốc . Hỏi vào lúc mấy giờ ô tô sẽ trở về đến A ? ĐS: .
BI TP P DNG Bi 1. 6 ( ) 120 km ! "#$%&'()"*+, 8 30 - *#." 30 /001&&2&'( ( ) #60 km h !34& 5 67+8&- 9.: ( ) #48 km h 11h00'- ! Bi 2. 3"&';+<!='> +5 ( ) 10 s !='>"?;&2&'> '@ ( ) 2 s !50 ( ) AB 32 m= ! "#$%&'()"&'- *#A&'>B&'>"C1DC*"5<- 9.: ( ) ( ) ( ) # # 8 80 3,2 m s m s m 3 3 - - ! Bi 3. &2DCE ( ) 100 km !FG EHI &2&'( ( ) #40 km h !J6"K1 1 5 DC ( 62@ 30 !34DC6"L&2&'( *"5<- 9.: ( ) # 160 53,33 km h 3 ; ! Bi 4. EHI&2&'( ( ) # 1 v 60 km h= *!M5 N 4"0O"<PE0+26O+5 K5P" t 6= !9*PQ()" K&1D ( ) # 2 v 90 km h= !34L*" K-K5P6O* ( ) L 15 km= ! 9.: ( ) # ' 2 v 100 km h= Þ A! Bi 5. 3"" ( ) 60 km !RL&'( ( ) #15 km h & <SKT!R"K8 62@U EVPTW!34"P&2(*,*"5< ;&2- 9.: ( ) # 2 v 20 km h= ! Bi 6. 3"+<;&2&'(KX! YJ1"B6" 15 K5PZ""P ( ) 25 km ! YJ;"B6" 15 K5PZ""TP ( ) 5 km ! $%&'()"/- 9.: ( ) # 1 v 40 km h= & ( ) # 2 v 60 km h= ! Bi 7. 3"K8 ;8"" 40km !J 1B6" 24 BN"!J;B6" 2 XKI"!$B&'()"/- 9.: ( ) ( ) 60 km , 40 km ! Bi 8. "+*!$50<"052J"[ O+5" 2 30 \+]>B+76"29[$\& 0 < 3 20 \&2&'(+2& E0!A5P@ @E0 UK!$%&'()""- 9.: ( ) #v 4 m s= ! Bi 9. "+*!$50G"052O[ J"+5" 2 40 \+]"'>+76"29[$\& 0< 2 &2&'(+2& E0!A5PZ"@ & E0 UK!$B&'()""- 9.: ( ) #23 km h ! Bi 10. "+*&2&'(KX ( ) #27 km h ! $50G052O[J"+5" 4 +]"'>+7 6"29[$\& 0< 3 ?&2&'( ( ) #27 km h & E 0!$%K5P@@E0- 9.: ( ) 2,25 km ! Bi 11. JQ 1946 "5K5P$+9[N$+Q*,K^'P 06L+"E"+!$%_+"E"++"$+9+&2&'( ( ) # 8 c 3.10 m s= P0+<*N)"N$+Q& +80$+9!$%_P01 '6" ( ) 2,5 s K+!`5$+9& N$+QLE0BG* K%G1 ( ) Ð R 6400 km= & ( ) T R 1740 km= !3C%K5PEZ" "\- ab:J*IP0""6+"51K5P &2 %2c! 9.: ( ) d 383140 km= ! Bi 12. 0+5 5 !3"G0&2&'( ( ) #60 km h d 3 6" &2&'( ( ) #40 km h !$%&'(+*B)"+56(" - 9.: ( ) # tb v 48 km h= ! Bi 13. &2&'( ( ) #60 km h +<e"GG)"50! $+5e"50f0e""G&2&'( ( ) #40 km h & e""6"&2&'( ( ) #20 km h !$%&'(+*B)"- 9.: ( ) # tb v 40 km h= ! Bi 14. 0 ( ) 50 km G<&2&'( ( ) ( ) # 25 km h ; 70 km 6"&2 &'( ( ) #35 km h $%&'(+*B)"+56(DC - 9.: ( ) # tb v 30 km h= ! Bi 15. 0+5g!$+5WG0&2&'( ( ) #20 km h d+5hK &2&'( ( ) #30 km h d+5(&2&'( ( ) #14 km h !$%&'(+ *B)"+56("- 9.: ( ) # tb v 24 km h= ! Bi 16. 0 1 3 DCG<&2&'( ( ) # 1 30 km h ; 3 DC K&2&'( ( ) #20 km h dGf0&2&'( ( ) #10 km h !$%&' (+*B)"+56("- 9.: ( ) # tb v 16,36 km h= ! Bi 17. 0+<50J!$+< 1 3 50G&2 &'( ( ) #15 km h & 1 3 505&2&'( ( ) #10 km h DC f0&2&'( ( ) #5 km h !$%&'(+*B)"0+<P 50J- 9.: ( ) # tb v 8,18 km h= ! Bi 18. 0 1 2 DCG<&2&'( ( ) #12 km h ; 1 2 f0 0&2&'( ( ) #20 km h !$%&'(+*B)"+56(DC - 9.: ( ) # tb v 15 km h= ! Bi 19. 5!Je"50G &2&'(+*B ( ) #8 km h !$+<50f0Be""G &2&'(+*B ( ) #5 km h & e""6"&2&'( ( ) #3 km h !$B &'(+*B)"L+<PDC- 9.: ( ) # tb v 5,33 km h= ! Bi 20. &'&<0+<50`M!$+<50L &2&'( ( ) #36 km h 45 +<50`&2&'( ( ) #40 km h +5 " 15 & +<50`M&2&'( ( ) #30 km h +5" 1 30 ! "#$%DC`M- *#$%&'(+*B)"L+<DC`M- 9.: ( ) ( ) # # # ABCD tb a s 82 km b v 32,8 km h= = ! Bi 116. &<*Q+<N<&2"( ( ) # 2 0,2 m s !346"*"5\ KP&<*0&'( ( ) #1 m s ! 9.: ( ) t 5 s= ! Bi 117. *OG"EG0i&2(*"G *, 0 !."LG1D""& &2K5P ( ) AB 19,2 m= ! $(0 ( ) #1 m s " ( ) 12 s !3C% "#b"()"- *#$"i& (0- 9.: ( ) ( ) ( ) # # # # 2 B a a 0,1 m s b t 22 s ; v 2,2 m s= = = ! Bi 118. "0&2&'( ( ) #10 m s BQ("EG 6" ( ) 20 s B0&'( ( ) #14 m s ! "#$%"()"- *#$%&'()"6" ( ) 40 s & DC1+5"L- 9.:"# ( ) # 2 a 0,2 m s= ! *# ( ) #v 18 m s= & ( ) s 560 m= ! Bi 119. Q(&2"(KX ( ) # 2 a 2 m s= !A"D" D"6L&2&'( ( ) #v 20 m s= !$+5" ( ) 6 s %D"D"6L1DC *"5< - 9.: ( ) s 84 m= ! Bi 120. @"0&2&'( ( ) #72 km h BC" 'EG& E06" ( ) 5 s !$%DC1+5 ( ) 5 s - 9.: ( ) s 50 m= ! Bi 121. f**OGQ(+C<+0><!jC 1+5\G< ( ) 10 cm !$%DC1+5h \G<& &'(L- 9.: ( ) ( ) #s 2,25 m , v 0,6 m s= = ! Bi 122. "&2&'( ( ) #8 m s BQ(& "EG6" ( ) 16 s &'()"L01 ( ) #12 m s !jC 1Q(K&'()"L0 ( ) #16 m s *"5<- 9.: ( ) s 384 m= ! Bi 123. "0&2&'( ( ) #72 km h BO'EG 0< ( ) 200 m Z"BE0! "#$%"()"& "O5KE- *#AOG*"5<"<1 ( ) 150 m - 9.:"# ( ) ( ) # 2 a 1 m s , t 20 s= - = ! *# ( ) t 10 s= ! Bi 124. "0&2&'( ( ) #10 m s BC"'EG & 6"K1 ( ) 84 m B&'(f ( ) #4 m s ! "#$%"()"- *#$%"C"1 ( ) 75 m - #$%"& DC1C" - 9.:"# ( ) # 2 a 0,5 m s= - ! *# ( ) t 10 s= ! # ( ) ( ) t 20 s , s 100 m= = ! Bi 125. 5 C"'EG& 5"&2&'(*" G ( ) #14,4 m s !$+5 ( ) 10 s G<KC"L150 E @50+5 ( ) 10 s 5 ( ) 5 m !$+5"*"5\K C"B E- 9.: ( ) t 80 s= ! Bi 126. "&2&'( ( ) #10 m s B(E( "EG(\E( ( ) 100 s & 0&'( ( ) #72 km s ! "#$%"()"- *#`E )"E( *"5<- #k(E(1 ( ) 625 m BLL&'( *"5<- 9.:"# ( ) # 2 a 0,1 m s= ! *# ( ) s 1500 m= ! # ( ) #v 15 m s= ! Bi 127. "&2&'( ( ) #72 km BP( 5KE0!+,6"DC ( ) 50 m &'(Pf e"!jC1&'(fe"5E0 *"5<- 9.: ( ) ( ) # 2 a 3 m s , s 16,67 m= - = ! Bi 128. "EG&2&'(& 5 & "("!."K 1DC ( ) 10 m BL&'( ( ) #5 m s <DC ( ) 37,5 m B&'( ( ) #10 m s !$%DC16" ( ) 20 s ! 9.: ( ) s 244,7 m= ! Bi 129. K8 i*X!AD"& L&'(G1 ( ) #8 m s & ( ) #12 m s !b"()" ( ) # 2 2 m s ! "#$%"+<50- *#$%K5Pi- 9.:"# ( ) AB t 2 s= ! *# ( ) ( ) AB OA s 20 m , s 16 m= = ! Bi 130. *XD"*(`M! +,: ( ) AB BC CD 5 m= = = !='(0` ( ) # C B D v v v 20 2 m s= + = ! "#$%"()"- *#$B"- 9.:"# ( ) # 2 a 4 m s= - ! *# ( ) AB t 1,6 s= ! Bi 131. *X6"K150 ( ) AB 36 m= G<&'()"P ( ) #14,4 km h !9<50 ( ) BC 28 m= &'()"0P< ( ) #4 m s !346"Lf 150E *"5<2E0- 9.: ( ) s 36 m= ! Bi 132. >86\"5">)"5 "& 5"+2 NB+5 ( ) 5 s & 5">"+5 ( ) 45 s !A E0G5"> ( ) 75 m !R 'EGCB"( )" - 9.: ( ) # 2 a 0,16 m s» - ! Bi 133. >86\"5">)"5 "& 5" D"+2NB+5" ( ) 4 s & 5">"+5 ( ) 10 s !A E0G5"> ( ) 144,5 m !R ' EGCB"()" - 9.: ( ) # 2 a 1,55 m s» - ! Bi 134. 5 ] 4 5"/5"E ( ) 10 m 'EG & 5"!D"6>*<+"5">D"+2O B+5" ( ) 1,7 s 5">"D"+2OB+5" ( ) 1,82 s ! "#$%"()"5 & ()"5 5">*OG "D"N D"6- *#$%"5"(;"D"+2ND"6- #$%K5PZ"G5">& D"6K5 E 0- 9.: ( ) ( ) ( ) ( ) # # # # # 2 o 4 a v 6,07 m s ; a 0,22 m s b t 2,162 s c 83,748 m= = - = ! Bi 135. 95 ]GKl5 9 5"!`E G & /5"*, ( ) 10 m ! 9G "D"D"6a><c+5 ( ) 2,1 s 5">D" D"6+5 ( ) 2 s !`P5 D"D"6+5*"5<\- 9.: ( ) 10 t 17,7 s= ! Bi 136. 9G Kl55 9 5"!9G & /5" E ( ) 10 m !9G D" D"6><+5 ( ) 4 s !$5"(;D"D"6+5 ( ) 2 s !$B&'()"5 KL&"2D"6- 9.: ( ) # o v 2,3 m s= ! Bi 137. >D"65 "'EG& 5 "!`E /5" l *4D"E 50(Z""5"!$5"> D"N""+5 ( ) 20 s !$5">"D"N""+5 ( ) 25 s !345">*" &1D"N""+5*"5\- 9.: ( ) t 38,7 s= ! Bi 138. >86\"B5 *"EG!$5" ( ) 1 D"+2N+5 ( ) t s !345">D"+2N +5*"5\- 9.: ( ) ( ) n t t n n 1 , s= - - ! Bi 139. &'"EG&2"("+0>< & 1DC6+5"!3C%: "#A5P"&' ( ) 1 m G<- *#A5P"&' ( ) 1 m (;- 9.: ( ) # # 1 2 2 a t s b t s s 1 s a a éù éù = D = - - êú êú ëû ëû ! Bi 140. &'*OG"EG+0><& 1 DC6+5" ( ) 4 s !$B" &'1+5 3 4 6")" 506- 9.: ( ) t 2 s= ! Bi 141. &'*OG"EG+0><& 1 DC6+5" ( ) 6 s !$B" &'1+5 3 4 6")" 506- 9.: ( ) t 3 s= !