A 3 kg bowling ball is thrown onto a mattress. If it takes 0.3 seconds to stop the ball using a force of 24 N, what was the initial velocity of the bowling ball when it first touched the mattress?
A 3 kg bowling ball is thrown onto a mattress. If it takes 0.3 seconds to stop the ball using a force of 24 N, what was the initial velocity of the bowling ball when it first touched the mattress?
Answer:
2.4 m/s
Explanation:
Applying Newton’s second law of motion,
F = m(v-u)/t………….. Equation 1
Where F = force exerted on the ball, m = mass of the ball, v = final velocity of the ball, u = initial velocity of the ball, t = time required to stop the ball.
Note: Since the the ball come to stop, then v = 0 m/s.
F = -mu/t…………. Equation 2
make u the subject of the equation
u = -Ft/m…………. Equation 3
Given: m = 3 kg, t = 0.3 s, F = 24 N
Substitute into equation 3
u = -(24×0.3)/3
u = -2.4 m/s.
Note the negative sign tells that the initial velocity of the ball is in opposite direction to the force acting on the ball.