Need help with a 2d inelastic collision

  • Thread starter jacegalvin
  • Start date
  • #1

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?
 

Answers and Replies

  • #2
supratim1
Gold Member
279
1
the answer must be 8.5 m/s, i got the same by using vectors.
 
  • #3
8.5 seems correct
 

Related Threads on Need help with a 2d inelastic collision

  • Last Post
Replies
5
Views
6K
  • Last Post
Replies
6
Views
471
  • Last Post
Replies
8
Views
870
Replies
7
Views
960
Replies
1
Views
2K
  • Last Post
Replies
4
Views
2K
Replies
4
Views
715
Replies
6
Views
2K
  • Last Post
Replies
1
Views
3K
Replies
2
Views
2K
Top