Question

A 0.430kg soccer ball is initially moving at 2.20m/s . A soccer player kicks the ball, exerting a constant 39.0N force in the same direction as the ball's motion.

Over what distance must her foot be in contact with the ball to increase the ball's speed to 5.95m/s ?

Answer 1

use E=1/2*m*v^2

Answer 2

use E=1/2*m*v^2

Eball= 1/2*.430*2.20^2= 1.0406

THen find force : M*A=E -> sfa A=E/M

1.0406/.430=2.42 N

Since the foot has 39 N and you want 5.95m/s

use F*D= 1/2*m*v^2

39*x= 1/2*.430*5.95^2

Solve for x
x = .195

I think