Đề thi môn cơ lý thuyết - để 1 pps

Tnrilng DHSP TP. HCM ' Khoa Vat LY pi, rm lr,rON, cd Lf THUYET Thdi gian: 90 Phrit CAu 1: Thdnh l{p phtfdng trinh Lagrange loai hai' Cflu 2: Chdt didm khdi lugng m chuydn d6ng dudi tdc dung duy nh6't cfia lgc hrit xtrydn tdrn a- f - -nta) r gtz nhhng sd d le , t ld brin kinh vecrd ndi tu gdc o cd oinh ld tf;m cfla tnldng hJc rldn vi tri cria chdt tlidm) a) Chrlng minh.ring chdt didm chuydn d6ng trong I m{t phEng cd Ainn' Xdc clinh rnit phfrng ndy. a b) Chgn oxy ld m4t ph8ng cd Oinn n6i tr€n, tim phtltJng trinh qu! tt4o cfia chd't didm vtli circ cliiSu kiQn ban ctdu: dx dv ,^, x(0)= a,ft(O)=0 ,Y (0) =0,;(o)=vu c) Tim cd ndng cfia hQ. CAu 3: Eia trbn rtdng chdt tam O, brin kinh R, khdi lttgng m'c6 thd quay drrgc qlunt trUc I nhm ngang, uu6ng,g!9-_n,d!-m,at rfia.rui cl1-gtra I didm'A tr€n vi1h dia' Lirc ddu' clla cltldc k6o 'ror, .fro OA hQp vdi phddng thing rlting mQt c6c 0o roi tnfr nhg' Chgn toa 'lO suy rQ'g li g,Jc l€ctr Q g16aOA vtli phddng thing tlfrng taithiti didm bdt k!. a) Tim hdm Lagrange cfia cd hQ' b) X6c ttinh phiong trinh chuydn dQng ctla tlia ndu ^"* 9O ld g6c nh6. c) Ndu trgc A chuydn clQng 6du tr€' dddng trdn nim trolg m{t phing chuydn d6ng cfra dta vdi bdn kinh a vi van tdc 76c Os ,t\mv$n tdc tAm O ctia dia. I = J/ry\ u" -r Lg JruY 6 . I nhm ngang, uu6ng,g! 9-_ n,d!-m,at rfia.rui cl1-gtra I didm'A tr€n vi1h dia' Lirc ddu' clla cltldc k6o 'ror, .fro OA hQp vdi phddng thing rlting mQt c6c. Phrit CAu 1: Thdnh l{p phtfdng trinh Lagrange loai hai' Cflu 2: Chdt didm khdi lugng m chuydn d6ng dudi tdc dung duy nh6't cfia lgc hrit xtrydn tdrn a- f - -nta). roi tnfr nhg' Chgn toa 'lO suy rQ'g li g,Jc l€ctr Q g16aOA vtli phddng thing tlfrng taithiti didm bdt k!. a) Tim hdm Lagrange cfia cd hQ' b) X6c ttinh