Calculating Maximum Acceleration and Speed for a 200kg Load with a 5kW Winch

[furor celtica]

Homework Statement

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.

Homework Equations

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?

 

[gneill]

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

 

[furor celtica]

just g=10 ms^2

 

[gneill]

just g=10 ms^2

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

 

[furor celtica]

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

 

[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?