Question

An object of mass $m=5\text{kg}$ is being pulled up a rough inclined plane which is at ${45}^{\circ }$ to the horizontal. The object is moving at an acceleration of $2{\text{m/s}}^2$ along the inclined plane. The coefficient of kinetic friction between the object and the plane is $0.2$. Calculate the total work done in pulling the block by $0.5\text{m}$. ($g=10{\text{m/s}}^2$)

• A. $7\text{J}$
• B. $10\text{J}$
• C. $5\text{J}$
• D. Zero

Answer 1

The correct option is C $5\text{J}$

From Newton's second law, $\sum F=ma=5\times 2=10\text{N}$
Hence work done by this force is $W=F\times d=10\times 0.5=5\text{J}$