1. Sep 5, 2011

### furor celtica

1. The problem statement, all variables and given/known data

A winch is used to raise a 200 kg load. The maximum power of the winch is 5 kW. Calculate the greatest possible acceleration of the load when its speed is 2 ms^1, and the greatest speed at which the load can be raised.

2. Relevant equations

3. The attempt at a solution

Alright so this is how I went about things: power=force x velocity, so upward force = 5000/2 = 2500. So net upward force = 500 N, so greatest possible acceleration = 500/200 = 2.5 ms^2.
I know this is incorrect, where did I go wrong?

2. Sep 5, 2011

### Staff: Mentor

Were you expected to use g = 10m/s2, or a more accurate value such as g = 9.81 m/s2 ?

3. Sep 6, 2011

### furor celtica

just g=10 ms^2

4. Sep 6, 2011

### Staff: Mentor

Then I don't see anything wrong with your value for the acceleration when velocity is 2 m/s.

5. Sep 7, 2011

### furor celtica

on another site i got the same answer.
i guess its a typo, thanks for your time

6. Sep 12, 2011

### furor celtica

alrighty now i've got an issue with ths second problem, finding the greatest speed at which the load can be raised
so greatest speed means the upwards force is equal to the downwards force, so the upwards force will be 2000N
power being 5000, speed is 2.5 ms^1
however the answer is 2.55, another typo or did i truly get it wrong this time?