All we need is the momentum before and after.
Momentum = (mass) x (speed)
Before: = (80 kg) x (4.7 m/s) = 376 kg-m/s
After: = (80 kg) x (3.4 m/s) = 272 kg-m/s
Change in momentum = (376 – 272) = 104 kg-m/s
Notice that when you work with impulse, you’re USUALLY calculating
(force) x (time).
The force is in Newtons, and the time is in seconds,
so the impulse is usually in units of
So how can I say that impulse and change of momentum are
the same thing ? Am I trying to pull a fast one on you ?
Remember that 1 Newton is 1 kg-m/s²
So (force) x (time)
= (Newton) x (second)
= (kg-m/s²) x (second) = kg-m/s .
and Momentum = (mass) x (speed) = (kg) x (m/s)
The units of impulse are the same as the units of momentum !
So when you give an object some impulse, you give it exactly
that much momentum.