# Mechanics Newton's 2nd law question

#### pianogirl

1. The problem statement, all variables and given/known data
A load of 200kg is lifted through 50m by a vertical cable. The load accelerates uniformly from rest for 20 seconds, travels at constant speed for 10 seconds then decelerates to rest in a further 10 seconds. Find the maximum speed attained and the tension in the cable at each stage.

2. Relevant equations
F=ma and maybe some SUVAT ones?

3. The attempt at a solution
I started using F=ma so that for the first stage I got T=200a+1960 but soon after that I got a bit confused.

Help would be really appreciated because I'm stuck!
Thanks!

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#### tiny-tim

Homework Helper
Hi pianogirl!

Forget the tension … you need to find the acceleration before you can find the tension.

Write out the standard constant acceleration equations for the three stages of motion, plus the equation that says the three distances add to 50m.

What do you get?

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