## swimlife97 one year ago If you are given time and distance, you can determine power if you know force. watts. energy. joules.

1. theEric

Well, watts are the units of power, and joules are the units of energy, and this question isn't going for you knowing units. It wants you to know which physical concept is missing from knowing the power. You're down to "force" or "energy." Do you have a guess and a reason?

2. theEric

Hint:$P=\frac{W}{t}$

3. theEric

Want another hint?

4. swimlife97

5. theEric

Okay!$W=F\ d\ cos(\theta)$Put that in the power equation, if you need another hint.

6. swimlife97

Is it force?

7. theEric

Why do you guess "force"?

8. swimlife97

W=F d cos(θ) W is work in Joules; F is force through distance; Cos theta is cosine of an angle theta

9. theEric

So, you say the answer is force because, well, you need it. And I agree, you're totally right.

10. theEric

$P=\frac{W}{t}=\frac{F\ d\ cos(\theta)}{t}$so you know distance and time, you just need force. The equations can be telling!

11. swimlife97

Okay thank you :)

12. theEric

You're welcome! :)

13. theEric

And congrats, because you did it! I just posted equations, haha.