Question

$R=10m$

Find work done by 50 N on the block

Answer 1

400 J

Answer 2

The force is horizontal; only the horizontal component of the displacement contributes to the work.

From the geometry, the horizontal displacement from point A to point B is

$$\Delta x = R\sin(53^\circ) = 10\,\text{m}\times\sin(53^\circ).$$

Using $\sin(53^\circ)\approx0.8$, we get

$$\Delta x \approx 10\times0.8 = 8\,\text{m}.$$

Thus, the work done by the 50 N force is

$$W = F\,\Delta x = 50\,\text{N}\times 8\,\text{m} = 400\,\text{J}.$$

Horizontal displacement = $10\sin(53^\circ) \approx 8\,\text{m}$; work done = $50\times8 = 400$ J.