Question

A block of mass $10kg$ is pulled by force $F=100N$. It covers a distance $500m$ in $10sec$. From initial point. This motion is observed by three observers A, B and C as shown in figure.
Find out work done by the force F in $10s$ as observed by C.

• A. $0J$
• B. $50000J$
• C. $20000J$
• D. $40000J$

Answer 1

The correct option is A $0J$

$(W_F{)}_{onblockw.r.t.A}=FS=100\times 500J=50,000J$
$(W_F{)}_{onblockw.r.t.B}=FS=100[500-10\times 10]=40,000J$
$(W_F{)}_{onblockw.r.t.C}=FS=100[500-500]=0$