List of top Physics Questions on Reflection Of Light By Spherical Mirrors asked in BITSAT

A simple pendulum doing small oscillations at a place \( R \) height above the Earth's surface has a time period of \( T_1 = 4 \, {s} \). \( T_2 \) would be its time period if it is brought to a point which is at a height \( 2R \) from the Earth's surface. Choose the correct relation [\( R \) = radius of Earth]:
A spherical ball of mass \( 20 \) kg is stationary at the top of a hill of height \( 100 \) m. It rolls down a smooth surface to the ground, then climbs up another hill of height \( 30 \) m and finally rolls down to a horizontal base at a height of \( 20 \) m above the ground. The velocity attained by the ball is: