Newton's law problems need help!!!!
Favorites|Homepage
Subscriptions | sitemap
HOME > Physics > Newton's law problems need help!!!!

Newton's law problems need help!!!!

[From: ] [author: ] [Date: 11-11-06] [Hit: ]
Therefore,(46.8 kg)*(9.8 m/s^2) = 458.The question gives us the force of static friction which is 347 N so now we can solve.coefficient of static friction = 347 N/ 458.......
A crate of 46.8kg - tools rests on a horizontal floor. You exert a gradually increasing horizontal push on it and observe that the crate just begins to move when your force exceeds 347N . After that you must reduce your push to 209N to keep it moving at a steady 28.8 cm/s .

a) What is the coefficient of static friction between the crate and the floor?

b) What is the coefficient of kinetic friction between the crate and the floor?

-
a) So we're trying to solve for coefficient of static friction which we will call (us) in this case. We know that

us = force of static friction/normal force

To find normal force we look at the vertical forces which in this case is normal force + force of gravity. Since the object isn't accelerating up and down the verical force is 0. Therefore,

force of gravity = normal force
mg = Fn
(46.8 kg)*(9.8 m/s^2) = 458.64 N = normal force

The question gives us the force of static friction which is 347 N so now we can solve.

coefficient of static friction = 347 N/ 458.64 N = 0.76

b) using the same method in a, this time you use the kinetic friction which is 209 N

coefficient of kinetic friction = 209 N/ 458.64 N = 0.46
1
keywords: 039,law,Newton,help,need,problems,Newton's law problems need help!!!!
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .