5.2 A pebble of mass 0.05 kg is thrown vertically upwards. Give the direction and magnitude of the net force on the pebble,

(a) During its upward motion

 

(b) During its downward motion

 

(c) At the highest point where it is momentarily at rest. Do your answers change if the pebble was thrown at an angle of 45° with the horizontal direction?

(Ignore air resistance.)

Two blocks of mass 10 kg and 5 kg are connected with a light string which passing over an ideal pulley attached with a fixed smooth wedge. If the system is released from rest, then the acceleration of the blocks will be

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Bullets of 0.03 kg mass each hit a plate at a rate of 200 bullets per second with velocity of 50 m/s and reflect back with velocity of 30 m/s. The average force acting on the plate in newton is

The root mean square speed of molecules of a gas is 1260 m/s. The average speed of the gas molecules is

Find the acceleration of 2 kg block shown in the diagram. (neglect friction)