What Went Wrong in Calculating the Velocity of Carts C and B After Collision?

Click For Summary
SUMMARY

The discussion centers on the calculation of the velocity of two colliding carts, C and B, after a collision. Cart C, with a mass of 2 tonnes and a velocity of 10 m/s, collides with Cart B, which has a mass of 3 tonnes and a velocity of 12.5 m/s, at a right angle. The correct final velocity of the combined carts after the collision is determined to be 7.8 m/s, contrary to the incorrect calculation of 8.5 m/s presented by the user. The discrepancy arises from a misunderstanding of momentum conservation principles and vector addition.

PREREQUISITES
  • Understanding of momentum conservation (P=mv)
  • Knowledge of vector addition in physics
  • Familiarity with right triangle properties and Pythagorean theorem
  • Basic principles of inelastic collisions
NEXT STEPS
  • Review the principles of momentum conservation in inelastic collisions
  • Study vector addition and its application in collision problems
  • Learn how to apply the Pythagorean theorem in physics contexts
  • Explore examples of two-dimensional collision problems in physics
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and collision theory, as well as educators seeking to clarify concepts related to momentum and vector analysis.

jacegalvin
Messages
2
Reaction score
0

Homework Statement

:
A cart 'C' mass of 2 tonnes is launched at 10m/s towards Cart 'B' which is 3 tonnes and moving at 12.5m/s. The angle between their paths of motion is 90 degrees. When the 2 carts collide, they remain stuck together. what is the velocity of the stuck together cart 'CB'
assuming no friction.


Homework Equations


P=mv
Pfinal=Pinitial
c= √b2+c2



The Attempt at a Solution



what i assumed was you could create a right angle triangle, with momentum of Cart C as one side, momentum of Cart B as another and the hypotenuse would be momentum of cart CB

So therefore:
Pbc= √Pb2+Pc2
Pbc=√(3000x12.5)2+(2000x10)2
Pbc=√1406250000+400000000
Pbc=4250
Pbc=m(c+b)v
4250=5000v
v=8.5m/s

but apparently the answer is 7.8m/s
what have i done wrong?
 
Physics news on Phys.org
the answer must be 8.5 m/s, i got the same by using vectors.
 
8.5 seems correct
 

Similar threads

Momentum with Two Carts on a Low-Friction Track
  • · Replies 3 ·
Replies
3
Views
5K
Impulse and Momentum: Ball and cart connected by a cord
  • · Replies 24 ·
Replies
24
Views
4K
Inelastic Collision: Cart of Mass m Hits Stationary Cart of Mass 2m
  • · Replies 2 ·
Replies
2
Views
11K
Angular speed calculation after an inelastic collision
  • · Replies 20 ·
Replies
20
Views
3K
What Are the Velocities After a Partially Inelastic Collision?
  • · Replies 8 ·
Replies
8
Views
2K
Velocity and Direction of a System after Inelastic Collision
  • · Replies 2 ·
Replies
2
Views
2K
Is my logic right for the answer to this inelastic car collision question?
  • · Replies 3 ·
Replies
3
Views
7K
Elastic and Inelastic Collisions in One Dimension - Need Help, due tonight
  • · Replies 17 ·
Replies
17
Views
4K
What is the velocity of cart B after the boy lands on it?
  • · Replies 1 ·
Replies
1
Views
4K
Collision Physics Homework: Calculating Speed of Center of Mass for Cart A and B
  • · Replies 1 ·
Replies
1
Views
6K