- #1
Pochen Liu
- 52
- 2
Homework Statement
I understand that if the change in impulse is 0.25, that because disc B is originally stationary the momentum disc B will have is equal to the impulse.
My question is how do we do this in terms of change in momentum?
Homework Equations
ΔP = Pf - Pi
P = mv
The Attempt at a Solution
ΔP = Pf - Pi
0.25 = Pf - (0.517 * 1.21)
Pf = 0.87557
Ps of the system = 0.62557
Ps = Pa + Pb = 0.87557 + Pb = 0.62557
Pb = -0.25
vb = -0.365
Why does this approach give the negative version of the answer?
I know what I've done isn't quite right because (Ps = Pa + Pb = 0.87557 + Pb = 0.62557) essentially states somehow the momentum in the system has increased with no external torque.