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

Answer:

90 N

Explanation:

The force applied to the ball is given by:

$F=\frac{\Delta p}{\Delta t}$

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

$F=\frac{9 kg m/s}{0.10 s}=90 N$