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Mechanics Newton's 2nd law question

  • Thread starter pianogirl
  • Start date
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!


Science Advisor
Homework Helper
Hi pianogirl! :smile:

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

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? :smile:

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