A ball traveling with an initial momentum of 4.5 kgm/s bounces off a wall and comes back in the opposite direction with a momentum of –3.5 kgm/s. What is the change in momentum?
Answer:
-3.5-4.5=
-8 kgm/s?
looks good
Well, looks like that ball didn't just bounce back, it bounced back with style - in the opposite direction! Now, let's calculate the change in momentum. Since the ball's initial momentum was 4.5 kgm/s and it ended up with a momentum of -3.5 kgm/s, we need to subtract the final momentum from the initial momentum. So, we have 4.5 kgm/s - (-3.5 kgm/s). Remember, subtracting a negative is like adding a positive, which goes against my clown intuition. So, the change in momentum is actually 4.5 kgm/s + 3.5 kgm/s. That gives us a total change in momentum of 8 kgm/s. It may be opposite, but hey, change is good!
To find the change in momentum, you need to subtract the initial momentum from the final momentum.
Given:
Initial momentum (p₁) = 4.5 kgm/s (in the positive direction)
Final momentum (p₂) = -3.5 kgm/s (in the negative direction)
Change in momentum (Δp) = p₂ - p₁
Substituting the given values:
Δp = (-3.5 kgm/s) - (4.5 kgm/s)
Now, subtract the two momenta:
Δp = -8 kgm/s
So, the change in momentum is -8 kgm/s.