AIIMS (All India Institute of Medical Sciences) Physics: Questions 302 - 306 of 500

For sky wave propagation of a 18 MHz signal, what should be the minimum electron density in ionosphere –

A bullet loses of its velocity when it passes through a plank. Find the maximum number of planks through which it can pass.

A boy standing on a long rail road car throws a ball up (straight) with a velocity. The car is moving on the horizontal road with acceleration 3, How far behind the boy will the ball fall?

A body is thrown horizontally with a velocity from the top of a tower of height h. It strikes the level ground through the foot of the tower at a distance from the tower. The value of x is

In below figure between two rigid walls P and Q, a block of mass is moving with constant velocity , towards a spring of spring constant . The block is moving from P and strikes at the end R of the spring at distance . If the collision between the block and wall P is perfectly elastic, the time period T (in seconds) of the motion of the block will be –