204. The ratio of the accelerations of the particle stated in Q. 5.237 after 5 sec and 3 sec will be

A.2

B.3

C.4

D.5

205. A ball is dropped from a height of 2.25 m on a smooth floor and rises to a height of 1.00 m after the bounce. The coefficient of restitution between the ball and the floor is

A.0.33

B.0.44

C.0.57

D. 0.67.

206. A glass ball is shot to hit a wall from a point on a smooth floor. If the ball returns back to the point of projection in twice the time taken in reaching the wall, the coefficient of' restitution between the glass ball and the wall is

A.0.25

B.0.33

C.0.4

D.0.5

207. Ball A of mass 250 g moving on a smooth horizontal table with a velocity of 10 m/s hits an identical stationary ball B on the table. If the impact is perfectly elastic, the velocity of the ball B just after impact would be

A. zero

B. 5 m/sec

C. 10 m/sec

D. none of these.

208. A particle is dropped from the top of a tower 60 m high and another is projected upwards from the foot of the tower to meet the first particle at a height of 15.9 m. The velocity of projection of the second particle is

A. 16 m/sec

B. 18 m/sec

C. 20 m/sec

D. 22 m/sec.

209. Pick up the correct statement from the following;

A. If two equal and perfectly elastic smooth spheres impinge directly, they interchange their velocities.

B. If a sphere impinges directly on an equal sphere which is at rest, then a fraction -12 (1 ? e2) the original kinetic energy is lost by the impact.

C. If a smooth sphere impinges on another sphere, which is at rest, the latter will move along the line of centres.

D. All the above.

210. Two shots fired simultaneously from the top and bottom of a vertical tower with elevations of 30' and 45? respectively strike a target simultaneously. If horizontal distance of the target from the tower is 1000 m, the height of the tower is

A. 350 m

B. 375 m

C. 400 m

D. 425 m.

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