## anonymous 3 years ago A monkey uses a fishing pole to raise 750g of bananas up to his position 15m above the ground. If the monkey's power output was 330 W, how long did it take to reel in the bananas?

1. anonymous

W=f*d?

2. Shane_B

Let me restate that...calculate the PE :)

3. anonymous

Oh, okay. $PE=mg \Delta y$?

4. Shane_B

Yes $\Delta PE = mg\Delta h$

5. anonymous

Okay: $(750g)(9.81m/s^2)(15m)=110,362.5J$

6. Shane_B

Almost...your mass needs to be in kg. Anyway, you'll get 110.3625J

7. anonymous

So the mass would be 7.5 kg?

8. Shane_B

No :) 750g = 0.75kg

9. anonymous

Sorry, what is s?

10. Shane_B

seconds

11. Shane_B

$Watts=\frac{Joules}{second}$

12. anonymous

and that would be equal to 330W

13. Shane_B

To be more clear:$330W=\frac{330Joules}{second}$

14. anonymous

Hm. That can't be right, can it? Perhaps: $330W=110.3625J/time (s)$

15. Shane_B

That's not what I'm saying :) I just showed the conversion of 330W to Joules/second

16. anonymous

Oh right, I guess I knew that.

17. Shane_B

So if you have 330J/s of power available and need to perform 110.3625J of work, how long would that take?

18. anonymous

36419.63 seconds?

19. anonymous

That seems really long.

20. anonymous

Also seems wrong.

21. Shane_B

22. Shane_B

$\frac{110.3625J}{330J/s}=?$

23. Shane_B

It will take about 1/3 of a second :)

24. anonymous

I got .3344 seconds. Don't know how I got so confused the first time around. Thanks for your help, Shane!

25. Shane_B

no problem. I get confused sometimes too...it's physics after all!