a teacher does 140 J of work in 20 s. How much power did he use?

power=workinJ/timeinSeconds

a teacher does 140 J of work in 20 s. How much power did he use?

To find out how much power the teacher used, we need to use the formula:

Power = Work ÷ Time

In this case, the work done by the teacher is 140 Joules and the time taken is 20 seconds. Plugging these values into the formula, we get:

Power = 140 J ÷ 20 s

Dividing 140 J by 20 s, we find:

Power = 7 J/s

So the teacher used 7 Watts of power.