Question

how much work did he do? Options 5 J500 J20 J10 JIf the sprinter were to decrease his time to 9.5s, how much less work would he need to do?

Answer 1

Given that the time is t = 10 s and the power is P = 50 W.

We have to find the work done.

The work done can be calculated by the formula

`\begin{gathered} P\text{ =}(W)/(t) \\ W=P* t \end{gathered}`

Substituting the values, the work done will be

`\begin{gathered} W\text{ = 50}*10 \\ =500\text{ J} \end{gathered}`

Thus, the work done will be 500 J

The work done when time t' = 9.5 s is

`\begin{gathered} W^(\prime)=50*9.5 \\ =475\text{ J} \end{gathered}`

The less work done will be W-W' = 500-475 = 25 J

Sprinter has to do 25 J less work.