Question

A small electric motor produces a force of 5 N that moves a remote-control car 5 m every second. How much power does the motor produce? Give your answer in watts and horsepower.

Answer 1

Answer:

25 W

or

0.0335 hp

Explanation:

Power: This can be defined as the rate at which work is done. The S.I ubit of power is Watt(W).

The expression for Power in terms of force and velocity is given as,

P = F×V.................. Equation 1

Where P = Power, F = force of the electric motor, V = Velocity of electric motor

Given: F = 5 N, V = 5 m/s.

Substitute into equation 2

P = 5×5

P = 25 W.

P = 25 W

or

P = 25(0.00134) horse power

P = 0.0335 hp

Hence the motor produce a power of 25 W or 0.0335 hp

Answer 2

Answer:

Explanation:

Given:

Force, f = 5 N

Velocity, v = 5 m/s

Power, p = energy/time

Energy = mass × acceleration × distance

Poer, p = force × velocity

= 5 × 5

= 25 W.

Note 1 watt = 0.00134 horsepower

But 25 watt,

0.00134 hp/1 watt × 25 watt

= 0.0335 hp.