Question

Question #0b531

Answer 1

Here's what I got.

Explanation:

You can find the work done by the force by looking at the displacement it produces.

You know that when a force `F` of `"100 N"` is pushing on the object for `"25 s"`, the object moves a total distance of `"5.0 m"`. In other words, the force produces a displacement of `"5.0 m"`.

To match your scenario with the diagram, when the force `F` pushes on the object, `x`, which can be calculated as `b - a`, will be equal to `"5.0 m"`.

The work done by the force `F` can be calculated by using the equation

`color(blue)(ul(color(black)(W = F * d * cosalpha)))`

Here

• `d` is the displacement produced by the force
• `alpha` is the angle between the direction of the force and the direction of the displacement

In this case, the force is acting on the horizontal, which means that you have

`alpha = 0^@ implies cos alpha = 1`

Therefore, the work done by the force will be

`W = "100 N" * "5.0 m" = color(darkgreen)(ul(color(black)("500 J")))`

Power on the other hand, is the rate at which the work is being done. The power generated by a force is equal to the work done by said force per unit of time.

In other words, power, `P`, tells you the rate at which energy is being consumed.

`color(blue)(ul(color(black)(P = W/t)))`

Here

• `t` represents the amount of time for which work is being done

In your case, you have

`P = "500 J"/"25 s" = color(darkgreen)(ul(color(black)("20 W"))) ->` here `"W"` represents joules per second, or watts