(a)[3]
Calculate the work done against friction as the block travels from $A$ to $B$.
(b)[4]
Use an energy method to determine the speed of the block at $B$.
Mathematics 9709 · AS & A Level · Energy, work and power
Energy, work and power — practice question
A block with mass $4\text{ kg}$ is drawn across a rough horizontal road by a constant force of magnitude $25\text{ N}$ acting at an angle of $36^\circ$ above the horizontal. The block travels in a straight line through two points $A$ and $B$ on the road, with $AB = 120\text{ m}$. The coefficient of friction between the block and the road is $0.4$. The speed of the block at $A$ is $7\text{ m s}^{-1}$.