Question

A block of mass $1kg$ is released from rest at $t=0$ to fall freely under gravity. Power of gravitational force acting on it at $t=2s$ is (in watt)

• A. $200$
  
• B. $100$
  
• C. $10$
  
• D. zero

Answer 1

The correct option is A $200$

Velocity of the block after 2 seconds $=v=gt=10\times 2=20m/s$

Power $=Fv=mgv=1\times 10\times 20=200W$

Hence correct answer is option $A$