Someone Else's Previous Q: https://www.physicsforums.com/showthread.php?t=61889(adsbygoogle = window.adsbygoogle || []).push({});

Diagram: http://www.webassign.net/pse/p12-11.gif

I'm using a different edition so some of the numbers are different. I'm doing this to review for the exam (it's not for hw).

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

Stephen is pushing his sister Joyce in a wheelbarrow when it is stopped by a brick 8.00 cm high. The handles make an angle of 15.0° from the horizontal. A downward force of 400 N is exerted on the wheel, which has a radius of 20.0 cm.

(a) What force must Stephen apply along the handles to just start the wheel over the brick?

(b) What is the force (magnitude and direction) that the brick exerts on the wheel just as the wheel begins to lift over the brick?

Assume in (a) and (b) that the brick remains fixed and does not slide along the ground.

2. Relevant equations

I guess just the summation of torque?

3. The attempt at a solution

I made a diagram showing the wheel hitting the brick and Stephen's force against the handlebar.

If I place the origin for determining the torque at the axle of the wheel, how can I determine the moment arm of Stephen's force with the given data?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Static eq problem

**Physics Forums | Science Articles, Homework Help, Discussion**