How much power is used if a machine does 28 J of work in 7 seconds? *

It’s either 4 or 196

4 j/s

To calculate the power used by a machine, you need to divide the amount of work done by the time it takes to do that work. In this case, the work done is 28 J and the time taken is 7 seconds.

The formula for power is:

Power = Work / Time

Plugging in the given values:

Power = 28 J / 7 s

Dividing 28 J by 7 s, we get:

Power = 4 J/s

Therefore, the machine uses 4 Joules of power per second.