Find the momentum of a 50g bullet whose kinetic energy is 250J.
Answers
Answer:
Basic Linear Formulas: (Rotational are different)
Momentum = mass * velocity = mv
Kinetic Energy (KE) = 0.5 * mass * velocity^2
..Note: symbol ^2 means squared so v^2 = v * v
Notice that (mass * velocity) is in both formulas
Re-arranging (KE) formula to solve for velocity:
[velocity * velocity] = 2 * (KE)/mass
- if we know mass = 0.05 kg and KE = 250 Joules
- then [velocity * velocity] = 2 * 250J / 0.05kg = 10000 J/g
- so velocity = 100 m/s
....Note: symbol ^(0.5) means 'square-root', so (25)^(0.5) = 5
- so momentum = mv = 0.05kg * 100 m/s = 5 kg * m/s
There is another way to get momentum from KE & mass:
momentum * momentum = (mv)(mv) = momentum^2
KE = 0.5 * [(mv)(mv)]/m = 0.5 * (momentum^2)/m
Re-arranging to solve for momentum:
momentum^2 = 2 * m * (KE) = 2 * 0.05kg * 250J = 25 gJ
- so momentum = (25 gJ)^(0.5) = 5 kg * m/s
Note: momentum is a vector so includes magnitude & DIRECTION
Both ways gave the same answer, so it verifies the answer
Mark me as brainliest please