Question

Calculate the work done to take an object of mass 20 kg to a height of 10 m. (g = 9 8 m/s²)

Answer 1

Suppose mass of the object (m) = 20 kg, while height (s) = 10 m

given that g = 9.8 m/s²

The value for F = mg

= 20 × (-9 8)

(Because the displacement is opposite the direction of the force, the negative sign is mentioned.)

Hence, F = -196 N

Now, W = F s

= -196 ×10

Thus, W = -1960 J

(The negative sign appears because the direction of force is opposite to the direction of displacement so that the work done is negative.)