Splung.com Physics Forum
Discuss physics or ask questions. Part of the Splung.com physics web site.

Author Message
Delilah

Joined: 29 Mar 2010
Posts: 6
Location: Whiteville

 Posted: Tue Mar 30, 2010 8:23 pm    Post subject: Help Physics! A 1420-kilogram car, moving with a speed of 15.0 m/s, is on a flat, circular curve having a radius of 50.2 meters. How much friction is needed to keep the car on the road?___________N What is the coefficient of friction between the tires and the road?_______
hepcj

Joined: 23 Jun 2007
Posts: 125

 Posted: Tue Mar 30, 2010 10:29 pm    Post subject: m =1420 kg v= 15 m/s r = 50.2 The force pushing the radially outward is F = (m v^2)/r = 1420 x (15^2)/50.2 = 6364.54 N The car is kept on the track by the frictional force of the tyres opposing the centrifugal force F. The frictional force is related to the weight by F_fric = mu F_norm. where mu is the coefficient of friction. Since the car is on a horizontal track, the magnitude of the normal force is: F_norm = mg 1420 x 9.8 = 13916 N Therefore, the coefficient of friction = 6364.54 N/13916 N = 0.46
Delilah

Joined: 29 Mar 2010
Posts: 6
Location: Whiteville

 Posted: Wed Mar 31, 2010 1:35 am    Post subject: thanks so much, im having a time trying to grasp Physics
 Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First
 All times are GMT Page 1 of 1