applesjgtl 2 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. applesjgtl

W=f*d?

2. Shane_B

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

3. applesjgtl

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

4. Shane_B

Yes $\Delta PE = mg\Delta h$

5. applesjgtl

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. applesjgtl

So the mass would be 7.5 kg?

8. Shane_B

No :) 750g = 0.75kg

9. applesjgtl

Sorry, what is s?

10. Shane_B

seconds

11. Shane_B

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

12. applesjgtl

and that would be equal to 330W

13. Shane_B

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

14. applesjgtl

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. applesjgtl

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. applesjgtl

36419.63 seconds?

19. applesjgtl

That seems really long.

20. applesjgtl

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. applesjgtl

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!