CBSE
Two masses M and M/2 are joined together by means of light inextensible string passed over a frictionless pulley as shown in the figure. When the bigger mass is released, the small one will ascend with an acceleration of
g
A player caught a cricket ball of mass 150 g moving at the rate of 20 ms-1 . If the catching process be completed in 0.1 s, the force of the blow exerted by the ball on the hands of the player is
0.3 N
30 N
300 N
3000 N
A uniform metal chain is placed on a rough table such that one end of it hangs down over the edge of the table. When one-third of its length hangs over the edge, the chain starts sliding. Then, the coefficient of static friction is
An athlete throws a discus from rest to a final angular velocity of 15 rad/s in 0.270 s before releasing it. During acceleration, discus moves a circular arc of radius 0.810 m. Acceleration of discus before it is released is
45
182
187
192
An ice cart of mass 60 kg rests on a horizontal snow patch with coefficient of static friction . Assuming that there is no vertical acceleration, find the magnitude of the maximum horizontal force required to move the ice cart. (g= 9.8 ms-2)
100 N
110 N
209 N
196 N
A boy of mass 40 kg is climbing a vertical pole at a constant speed. If the coefficient of friction between his palms and the pole is 0.8 and g = 10 m/s2, the horizontal force that he is applying on the pole is
300 N
400 N
500 N
600 N
A cyclist is moving in a circular track of radius 80 m with a velocity v = 36 km/h. He has to lean from the vertical approximately through an angle (Take g = 10 ms-2)
From the top of tower, a stone is thrown up. It reaches the ground in t1 second. A second stone thrown down with the same speed reaches theground in t2 second. A third stone released from rest reaches the ground in t3 second. Then
If the earth were to suddenly contract to of its present radius without any change in its mass, the duration of the new day will be nearly
24/n h
24 n h
24/n2 h
24 n2 h
A cricket ball of mass 0.25 kg with speed 10 m/s collides with a bat and returns with same speed within 0.01 s. The force acted on bat is
25 N
50 N
250 N
500 N