Collisions PDF

7. A canon ball is fired with a velocity 200 m/sec at an angle of 60° with the horizontal. At the highest point of i...

7. A canon ball is fired with a velocity 200 m/sec at an angle of 60° with the horizontal. At the highest point of its flight. it explodes into 3 equal fragments, one going vertically upwards with a velocity 100 m/sec, the second one falling vertically downwards 5.12- COLLISIONS with a velocity 100 m/sec. The third fragment will be moving with a velocity 1. A stationary radioactive nucleus of mass 210 units dic: (@) 100 m/s in the horizontal direction into an alpha particle of mass 4 units and a rt pa of the alpha pbc of (b) 300 m/s in the horizontal direction mass 206 units. If the kinetic energy (¢) 300 m/s in a direction making an angle of 60° with the kinetic energy of residual nucleus is : hat the “ ea Cr (a) E/206 (b) 3 E/103 ( messed i a direction irecti making i an angle o wi/ith the (c) 2 E/NO03 (d) E/N03 two identi masses 200 and 400 gm 8. Two solid rubber balls A and B having of A ghey rest ws rr: respectively are moving in opposite direction with velocity — an inextensible pestring to 0-3 m/sec. After collision, the two balls come to rest by equal passing over a smooth when the velocity of B is : frictionless pulley. Mass (a) 0-15 m/sec (b) 1-5 m/sec P is given a downward (¢) - 0-15 m/sec (d) None of the above push with a eed ¥ as ¢ 9. A shell of mass m moving with velocity v suddenly breaks into 2 shown 1n Fig. 512.1. It J1P Qo pieces. The part having mass m/4 remains stationary. The velocity collides with the ren of the other piece will be and rebounds. at 2v happens immediately Floor ww ® 2 ay 3 d) 4 =v © =v after collision” (a) P and Q both move upwards with equal speeds 4 ’ and 10. A body of mass m strikes a stationary body of mass M one- (b) P and Q both move upwards with different speeds collision. After collision, m has a speed undergoes an elastic (c) P moves upwards and Q moves downwards with equal speeds third its initial speed. The ratio M/m is @ 1:2 Bb) 2:1 (d) Both P and Q are at rest 1:3 3:1 3. A bomb of mass 9 kg explodes into 2 pieces of mass 3 kg and mass 5 kg moving with a velocity 10 m/s collides with 6 kg. The velocity of mass 3 kg is 1-6 m/s, the K.E. of mass 6 kg is 11. A body of (0 rest. The (b) 961] another body of the mass 20 kg at rest and comes (a) 3-841] (d) 2927 velocity of the second body due to collision is (c) 1927 (AIPMT 2005 ; Karnataka CET 2007 ; Odisha JEE 2008) @): 23.08 hr Cris Eo Tamia (ly 10s (KCET 2001) 4. If a shell fired from a cannon, explodes in mid air,’ then 12. A ball falls from rest from a height 4 onto a floor, and rebounds to ' a height 4/4. The coefficient of restitution between the ball and (a) its total kinetic energy increases the floor is (b) its total momentum increases (a) 172 (b) 1/4 (c) its total momentum decreases © + @ 34 (d) none of these (Pb. PET 2004) spring. 5. Two unequal masses are tied together with a compressed 13. A ball of weight 0-1 kg coming with speed 30 m/s strikes with a When the cord is burnt with a match stick, releasing the spring, bat and returns in opposite direction with speed 40 nvs, then the the two masses fly apart with equal impulse is (Taking final velocity as positive) (a) momentum (b) speed (@) —0-1x (40) - 0-1 x (30) (c) acceleration (d) kinetic energy (b) 0-1 x (40) — 0-1 x (- 30) constant velocity u hits another 6. A sphere of mass /m moving with a (¢) 0-1 x (40) + 0-1 x (- 30) mass. If e is the coefficient of stationary sphere of the same (d) 0-1 x (40) — x (20) of two spheres after 0-1 ratio of the velocity restitution, then the hits a honzontal collision will be 14. A ball falling freely from a height of 4:9 m 3 =e 1+e surface. If e= rk then the ball will hit the surface second time (a) b) 7 l1+e 1-e after é+1 e-1p. (@ 05s (b) 15s (c) @ e +1 (c) 35s (d) 34s (DUMET 2005) e—1