posted by Anonymous .
A 109 kg fullback runs at the line of scrimmage.
(a) Find the constant force that must be exerted on him to bring him to rest in a distance of 1.1 m in a time interval of 0.22 s.
(b) How fast was he running initially?
Average V during deceleration = 1.1/0.22 = 5 m/s
Initial V = Vo = 2*Vav = 10 m/s
Deceleration rate = a = Vo/0.22s
= 45.5 m/s^2
Force = m*a