Rosie (mass 47 kg) pushes a box with a horizontal force of 140 N (31.472 lb) at a speed 15 m/min.

What is Rosie's power output?

To find Rosie's power output, we need to calculate the amount of work she does per unit of time. Power is defined as the rate at which work is done.

First, we need to find the work done by Rosie. The formula for work is given by:

Work = Force x Distance x cos(theta)

Where:
- Force is the horizontal force applied by Rosie (140 N).
- Distance is the distance over which the force is applied. In this case, the distance is not given directly, but we are given the speed at which Rosie pushes the box. Speed is defined as the distance covered per unit of time. So, we can calculate the distance by multiplying the speed (15 m/min) by the time interval over which the force is applied.
- The angle theta represents the angle between the force and the direction of motion. Since the box is pushed horizontally, theta is 0 degrees, and cos(0) = 1.

Now, let's calculate the distance:
Distance = Speed x Time

Given that the speed is 15 m/min, and we don't have the time interval, we need to convert the speed to meters per second (m/s) to maintain consistent units:
Speed = 15 m/min * (1 min/60 s) = 15/60 = 0.25 m/s

Next, we can calculate the time interval. Since we don't have it directly, we can assume that the time taken to cover the distance is the same as the time taken to exert the force. Therefore, we can use the formula:

Time = Distance / Speed

Plugging in the calculated values:
Time = Distance / Speed
Time = Distance / 0.25 m/s

Now, let's calculate the work done:
Work = Force x Distance x cos(theta)
Work = 140 N x Distance x 1

Finally, we need to find the power. Power is defined as the work done per unit of time:

Power = Work / Time

Plugging in the calculated values for work and time, we can find Rosie's power output.

power= force*velocity=140*15 watts