Answer:
1000 N
Explanation:
First, we need to find the deceleration of the running back, which is given by:
where
v = 0 is his final velocity
u = 5 m/s is his initial velocity
t = 0.5 s is the time taken
Substituting, we have
And now we can calculate the force exerted on the running back, by using Newton's second law:
so, the magnitude of the force is 1000 N.