Work = force x distance

Power = work / time

745 watts = 1 hp
A tow truck is hired to pull out a 2000 Kg Car from a 10 meter deep ditch straight up and place it on the level ground. If the work is completed by the truck in 5 seconds Calculate horse power of the truck.

horse power of the truck 39,000 kgm²s⁻³

Explanation:

Calculate horse power of the truck.

Work = force x distance

where,  force = mg = 2000 kg x 9.8 m/s² = 19,600 kgm/s²

            distance = 10 meter

Work = 19,600 kgm/s² x 10 meter

         = 196,000 kgm²s⁻²

Power = work / time

           = 196,000 kgm²s⁻² / 5 seconds

           = 39,000 kgm²s⁻³

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.