Question

A 0.45 kg soccer ball changes its velocity by 20.0 m/s due to a force applied to it in 0.10 seconds. What force was necessary for this change in velocity?

Answer 1

Know that change in momentum = impulse (Δp = F*t), momentum is mass*velocity, and impulse is force*time

Δp = F*t

`m_}}v__(f)} - m_}}v__i}} = Ft \\ m(v__f}}-v__i}}) = Ft \\ (0.45kg)(20 m/s) = F(0.10s) \\ F = 90N`.

Answer 2

90 N

Step-by-step explanation:

The force applied to the ball is given by:

`F=(\Delta p)/(\Delta t)`

where

`\Delta p` is the change in momentum of the ball

`\Delta t` is the time taken

The change on momentum of the ball is:

`\Delta p=m\Delta v=(0.45 kg)(20 m/s)=9 kg m/s`

So, the force applied is

`F=(9 kg m/s)/(0.10 s)=90 N`