Question

A force of 110 N is applied horizontally to the handles of a lawnmower to move it at a speed of 0.80 m/s across a lawn. Find the power used to mow the lawn.

Answer 1

The power used to mow the lawn, with a force of 110 N applied to move the lawnmower at 0.80 m/s, is calculated using the formula P = F × v and results in 88 Watts.

Step-by-step explanation:

To calculate the power used to mow the lawn, we use the formula for power, which is the rate of doing work. Power (P) is equal to the work done (W) divided by the time taken (t), or P = W/t. In this case, work done can also be described as the force applied (F) times the distance moved (d) in the direction of the force, but since the problem doesn't provide the distance and only provides the speed at which the lawnmower is moving, we can use another formula for power: P = F × v where v is velocity.

Given that the force (F) is 110 N and the velocity (v) is 0.80 m/s, we can find the power with P = 110 N × 0.80 m/s giving us:

P = 88 Watts.

This is the power used by the person to mow the lawn while applying a constant horizontal force to move the lawnmower at a constant speed.

Answer 2

Power is the rate of doing work, P = W/t. As is implied by the equation for power, a unit of power is equivalent to a unit of work divided by a unit of time. We calculate as follows:

P = W/t = Fd/t where d/t = v
P = Fv = 110(80)
power is 8800 watts