Laws of Motion ...

A ball of mass 400 g is dropped from a height of 5 m. A boy on the ground hits the ball vertically upwards with a bat with an average force of 100 N so that it attains a vertical height of 20 m. The time for which the ball remains in contact with the bat is [g = 10 m/s²]

The linear momentum p of a body moving in one dimension varies with time according to the equation p = a + bt², where a and b are positive constants. Thenet force acting on the body is

A body is imparted motion from rest to move in a straight line. If it is then obstructed by an opposite force, then

The adjacent figure is the part of a horizontally stretched net. Section AB is stretched with a force of 10 N. The tensions in the sections BC and BF are

A second pendulum is mounted in a rocket. Its period of oscillation decreases when the rocket

A particle moves in the xy–plane under the action of a force Fsuch that the components of its linear momentum p at any time t are p_x = 2 cost, p_y = 2 sin t. The angle between F and p attime t is

A cricket ball of mass 250 g collides with a bat with velocity 10 m/s and returns with the same velocity within 0.01 s. The force acted on bat is

A pendulum bob of mass 50 g is suspended from the ceiling of an elevator. The tension in the string if the elevator goes up with uniform velocity is approximately

A ball of mass 0.5 kg moving with a velocity of 2 m/s strikes a wall normally and bounces back with the same speed. If the time of contact between the ball and the wall is 1 ms, the average force exerted by the wall on the ball is

An automobile travelling with a speed of 60 km/h, can brake to stop within a distance of 20 m. If the car is going twice as fast, i. e., 120 km/hr, the stoppingdistance will be