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Momentum - collision

  • Thread starter Ginerva123
  • Start date
[SOLVED] Momentum - collision

1. The problem statement, all variables and given/known data

An object of mass 950kg travelling east collides with an object of mass 1900kg travelling north. The two objects then move off together at 16m/s in a direction of 24degrees east of north. Find their respective velocities prior to the collision.

2. Relevant equations

p = mv

3. The attempt at a solution
Momentum after collision = 2850 x 16 = 45600
As momentum is a vector, then breaking it into its components we get:
Object 1: 950 x v1 = (45600)cos24 ... v1=43.85m/s
Object 2: 1900 x v2 = (45600)sin 24... v2=9.76m/s

I thought this seemed simple enough, but apparently the answers are wrong... can anyone see where I might have made mistake, or am I just going about it the wrong way altogether?
 

olgranpappy

Homework Helper
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1. The problem statement, all variables and given/known data

An object of mass 950kg travelling east collides with an object of mass 1900kg travelling north. The two objects then move off together at 16m/s in a direction of 24degrees east of north. Find their respective velocities prior to the collision.

2. Relevant equations

p = mv

3. The attempt at a solution
Momentum after collision = 2850 x 16 = 45600
As momentum is a vector, then breaking it into its components we get:
Object 1: 950 x v1 = (45600)cos24 ... v1=43.85m/s
Object 2: 1900 x v2 = (45600)sin 24... v2=9.76m/s

I thought this seemed simple enough, but apparently the answers are wrong... can anyone see where I might have made mistake, or am I just going about it the wrong way altogether?
you got the sin/cos mixed up.... 24 degrees "east of north" is pointing more north than east...
 

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