A particle of mass 100 g is thrown vertically upwards with a speed of . The work done by the force of gravity during the time the particle goes up is
- (A)0.5 J
- (B)-0.5 J
- (C)-1.25 J✓ Correct
- (D)1.25 J
Answer: (C)
Solution
The particle rises until its speed falls to zero, climbing a height . Gravity points downward while the displacement is upward, so the work done by gravity during the ascent is negative: .
JEE Main · 2006 · 30 Apr 2006 · Offline · Single correct option