Homework Help: Physics

Posted by Bart on Tuesday, January 1, 2013 at 11:09am.

You slide your friend with a mass of 65 kg out of the way as they are blocking the exit and keeping you from escaping from physics class where you have been tormented by problems for the last hour and a half. The coefficient of kinetic friction between the floor and your friend's shoes is 0.45 and you are able to push with 650N. How long will it take you to get your friend to their next class that is 35m down the hall from rest? (Answer: 3.5 seconds) I have worked the problem and checked my math. I get 1.99 seconds.

Physics - Damon, Tuesday, January 1, 2013 at 11:17am
friction force = 65*9.81*.45 = 287 N

net force = 650-287 = 363 N

F = m a
a = 363/65 = 5.59 m/s^2

x = (1/2) a t^2
35 = .5 (5.59) t^2
t = 3.54 seconds
Physics - Bart, Tuesday, January 1, 2013 at 12:10pm
Thank you!

Answer this Question

Related Questions

Physics - It’s a beautiful winter day, and you and your friend are throwing...
physics - a 65 kg student, starting from rest , slides down an 8 meter high ...
physics - At a playground, a 19.8 kg child plays on a slide that drops through a...
physics - At a playground, a 19.8 kg child plays on a slide that drops through a...
Physics - At a playground, a 18.7 kg child plays on a slide that drops through a...
Physics - At a playground, a 18.7 kg child plays on a slide that drops through a...
physics - A student, starting from rest, slides down a water slide. On the way ...
physics - A student, starting from rest, slides down a water slide. On the way ...
Physics - A child with a mass of 83 kg is on top of a water slide that is 12 m. ...
Physics - A student, starting from rest, slides down a water slide. On the way ...

For Further Reading

First Name:
School Subject:
Answer: