The force required to keep a body moving in uniform velocity on a frictionless surface is MCQ with Answer and Explanation

Explanation:
Escape velocity (Ve) is the minimum velocity needed to overcome Earth's gravitational pull so that final velocity at infinity is zero. If launched with velocity v > Ve, the body will escape and, due to conservation of energy, retain a residual speed (v_infinity) at an infinite distance, calculated by v_infinity = √(v² - Ve²). Here, v = 2Ve, so it retains speed.

Explanation:
Force (weight) is vertical (upward to support), displacement horizontal, angle 90°, cos90°=0, work = 0. No work against gravity because vertical height doesn't change. Energy spent is internal muscular effort, but physics work zero.

Explanation:
0.5 kW × 2 h = 1 kWh.