Recoil (AP)
AP Momentum
AP Physics: Conservation of Momentum — Head-on Elastic Collisions
What Is an Elastic Collision?
Elastic Collision?
Combining the Equations
Combine the energy equation above with conservation of momentum
m1v1 + m2v2 = m1v1' + m2v2'
...you get .....
Problem 1
Giancoli — page 189, #23
m1 = .450 kg V1 = 3.00 m/s
m2 = .900 kg V2 = 0
Step 1
V1 - V2 = V2' - V1'
V2' - V1' = 3 m/s
V2' = 3 m/s + V1'
Step 2 — Total Mom before = Total Mom After
1.35 kgm/s = .45V1' + .90kg(3 + V1')
1.35 = 1.35V1' + 2.7
Step 3 — Since V2' = 3 m/s + V1', then ...
Collisions in 2 Dimensions
Total Mom in X direction before = Total Mom in X direction after
Total Mom in Y direction before = Total Mom in Y direction after
If angle between = 90 degrees ... Add vectors using ....
Problem 2
Textbook — page 190, #41
Total Momentum Before
Eagle 1: mv = 4.3 kg(7.8 m/s) = 34 kgm/s
Eagle 2: mv = 5.6 kg(10.2 m/s) = 57 kgm/s
Total Mom before:
a2 + b2 = c2
342 + 572 = c2
66 kgm/s = (5.6kg + 4.3kg)v
problem 42)
Related
Enrichment
Rifle Recoil — Dr. Dave's Hall of Fame