Friday

April 18, 2014

April 18, 2014

Posted by **Mary** on Saturday, February 11, 2012 at 10:47pm.

from rest at the top of the 60 m long hill which is inclined at an angle of 30o to the horizontal, and arrives at the bottom 8.0 s later. What is the coefficient of kinetic friction between the hill and the sled?

- Physics -
**drwls**, Saturday, February 11, 2012 at 11:47pmAssume that the acceleration is constant, such that

60 m = (a/2)t^2

a = 120/(8)^2 = 1.875 m/s^2

Then use Newton's second law in the form

Fnet = m*g sin30 - m*g*cos30*u = m*a

Note that the mass cancels out, which is good since they did not provide a value.

With the value of a that you now know, the friction coefficient u can be calculated.

0.50 g - 0.866 u*g = 1.875 m/s^2

8.49 u = 4.90 -1.875 = 3.02 m/s^2

u = 0.356

**Related Questions**

legal ethics - A child does not have his parental feild trip form and wants to ...

Physics - A child traveling 5m/s on a sled passes her younger brother.if her ...

Math - 104 students responses 21 liked sledding as their favorite winter ...

Physics - The sled is stuck in the snow. A child pulls on the rope and finds ...

science - Betty is sledding down a hill going 12 m/s. She hits a very steep ...

physics - A man swings his child in a circle of radius 0.75 m .If the mass of ...

10th grade - Suppose that a kid was casually sledding down a gentle slopping ...

Physics - A child with a mass of 83 kg is on top of a water slide that is 12 m. ...

urgent pls education - Assuming in your class,you have noticed that a particular...

physics - a man swings his child in a circle of radius .75 meters. if the mass ...