Wednesday
April 23, 2014

Homework Help: Physics

Posted by Anonymous on Saturday, July 27, 2013 at 12:09am.

A 77 kg sprinter is running the 100 m dash. At one instant, early in the race, his acceleration is 4.7 m/s^2.

a) What total force does the track surface exert on the sprinter? Assume his acceleration is parallel to the ground. Give your answer as a magnitude.

b) What total force does the track surface exert on the sprinter? Assume his acceleration is parallel to the ground, and give your answer as an angle with respect to the horizontal.

c) This force is applied to one foot (the other foot is in the air), which for a fraction of a second is stationary with respect to the track surface. Because the foot is stationary, the net force on it must be zero. Thus the force of the lower leg bone on the foot is equal but opposite to the force of the track on the foot. If the lower leg bone is 60 degrees from horizontal, what is the components of the legís force on the foot in the direction parallel to the leg? (Force components perpendicular to the leg can cause dislocation of the ankle joint.)

d) What is the components of the legís force on the foot in the direction perpendicular to the leg?

Can someone help me on this problem please? I tried googling it, and found I should use a^2 + b^2 = c^2 for A, but I'm so lost I don't even know what numbers I should be using to plug into that equation with.

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Physics (College) - One simple model for a person running the 100 m dash is to ...
Physics - n a running event, a sprinter does 5.5 105 J of work and her internal...
physics - In a running event, a sprinter does 4.9 105 J of work and her internal...
physics - A 79-kg sprinter accelerates from rest to a speed of 11.0 m/s in 4.8 s...
physics - A 79-kg sprinter accelerates from rest to a speed of 11.0 m/s in 4.8 s...
Physics - A particular sprinter reaches a horizontal acceleration of 13.3 m/s2 ...
chemistry - A sprinter set a high school record in track and field, running 200....
physics - A sprinter mass 72 kg runs the 50 meter dash in 8.35 s. Assume that ...
physics - At the instant a race began, a 74.0 kg sprinter exerted a force of 850...
physics - A sprinter can reach a speed of 12 m/s in 0.96 s. If the sprinterís ...

Search
Members