Q. The work done in pulling up a block of wood weighing $2\ kN$ for a length of $10\ m$ on a smooth plane inclined at an angle of $15{^\circ}$ with the horizontal is $\lbrack\sin{15{^\circ}} = 0.2588\rbrack$
A) $4.36\ kJ$
B) $5.17\ kJ$
C) $8.91\ kJ$
D) $9.82\ kJ$
Explanation
(b) $W = mg\sin\theta \times s$
$= 2 \times 10^{3} \times \sin{15{^\circ}} \times 10$
$= 5.17\ kJ$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.