- #1
aimen khattakk
- 17
- 1
Homework Statement
One car of mass 1400 kg is traveling at 45km/h when it collides and becomes entangles with another car mass of mass 1300 kg traveling at 39km/h[E]. What is their velocity after collision
So MA = 1400 kg
VA = 45kh/h
MB = 1300 kg
VB = 39 kh/h [E]
and After Collision:
MAB = 2700kg2. Homework Equations
P = mv
∑P = ∑P'
PA + PB = PAB'
3. The Attempt at a Solution
so I've always been told to solve momentum first so since car A is going South that means it only has a verticle momentum? so
that means PAY = m⋅v
so PAY = 63000kg⋅km/h
similarly for B
so only a horizontal momentum
so PAX = 50700kg⋅km/h [E]
so now I am stuck on what to do, i tried to find the momentum of Pab in the x and y direction then find pab and solve for v but that doesn't work when i tried it. Pab in the x direction just turns out to be the same as pb in the x direction and pab in y direction turns out to be pa in y direction and then using pythaguras theorum to find the hyp and hence find Pab i get 37396 kg⋅km/h and then solving for V by diving the Pab by the total mass of both of the cars together gives me a velocity of 13.85km/h but the answer is 30.0km/h so i think i messed up after solving my momentums for before the collision but idk what i did wrong
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