To solve this problem we will apply the concept related to the kinetic energy theorem. Said theorem states that the work done by the net force (sum of all forces) applied to a particle is equal to the change experienced by the kinetic energy of that particle. This is:


Here,
m = mass
v = Velocity
Our values are given as,


Replacing,


Therefore the mechanical energy lost due to friction acting on the runner is 907J
I believe you got it correct already
Roughly 115,200 times a day
Answer:

Explanation:
Acceleration, 
Where v and u are the final and initial velocities of the race car respectively, t is the time taken for the race car to attain velocity of 36 m/s.
Substituting 36 m/s for v, 28 m/s for u and 2 s for t then
