Problem 44PE

Integrated Concepts When starting a foot race, a 70.0-kg sprinter exerts an average force of 650 N backward on the ground for 0.800 s. (a) What is his final speed? (b) How far does he travel?

Solution 44 PE

a.)

Step 1 of 2

The final speed of the sprinter can be found using kinematic equation for one dimensional motion.

where, initial speed = 0 m/s

final speed

acceleration in m/s2

0.8 s

Now, we can find the acceleration using Newton’s second law of motion

where, F = Force exerted by the sprinter = 650 N

m = mass of the sprinter = 70 kg

a = acceleration

So,

=

= 9.28 m/s2