How Long Does It Take a Crane to Lift a Load to Maximum Velocity?

[tattersfield]

Homework Statement

hi there, really don't know how to attempt this, could someone please give guidance, thanks. a crane needs a force of 3kN to lift a mass of 6 tonne. if the load is initially at rest and the maximum velocity is 5m/s, determine the time taken to lift the load. Any help would b great, been on with this for 2 days now. thanks

Homework Equations

The Attempt at a Solution

 

[Kurdt]

Lift it how far? Or is it the time taken for the crane to accelerate the load to 5m/s?

 

[tattersfield]

im not sure, that is the question , just how i got it, i don't understand it at all

 

[Kurdt]

Well I'd imagine you have to calculate the time it takes to reach its maximum speed. Do you know of the kinematic equations?

 

[tattersfield]

no i am brand new to physics, do you know of a good site that coulld explain it to me? thank you for answering

 

[Kurdt]

Ok there are a list of the kinematic equations here:

https://www.physicsforums.com/showpost.php?p=905663&postcount=2

What you'll need to do is find the acceleration of the mass due to the force from the crane using Newtons second law. Once you have the acceleration you can put it into on of the kinematic equations to find the time taken to accelerate to 5m/s.

Like I say before the question isn't posed particularly well so I'm not surprised you're confused. Have a go anyway and if you need more assistance just ask.