Block A with a mass of 12kg moving at 2m/s makes a perfectly elastic head-on collision with block B, mass 36kg

Question

at rest. find the velocities of the block A after the collision. assume all motion is one dimension.

Answer 1

Here you must apply the concept of " conservation of linear momentum" and " Conservation of energy".
1) According to the conservation of linear momentum, the net momentum remains conserved if the net force acting on the particle is zero."
Thus, momentum before collosion = momentum after collision
therefore M1V1=M2V2.-----------------(1)

Since the collision is elastic thereby the kinetic energy will also be conserved.
therefore, M1(V1)^2= M2(V2)^2-------------(2)

here M1=12 ;M2=36 ;V1=2 and V2=?
Solving equations (1) and (2), you can easily get the answer.

Good Luck

Answer 2

Two concepts--conservation of energy and conservation of momentum.

Conservation of momentum:
Momentum before = momentum after
mass1 times its initial velocity plus mass2 times its initial velocity equals mass1 times its final velocity plus mass2 times its final velocity.

Conservation of energy:
Energy before = energy after.
The only relevant energy in this problem is kinetic.
So do just like momentum, except add up 1/2 mv^2's for each particle before and after.

You have 2 equations and 2 unknowns (the two final velocities). Use your algebra skills to find the velocities.

Answer 3

using the rule of linear momentum

m1*u1+ m2*u2= m1*v1+ m2*v2

m1=12 ,u1=2, m2=36 , u2=0
12*2+36*0=12*v1+36*v2
12*v1+36*v2=24 equation 1

using newtons law
v2-v1=-e(u2-u1)
e=1 (elastic collision)
v2-v1=-(0-2)
v2=2+v1 equation 2

from 1&2
12*v1+36(2+v1)=24

v1=-1
ie velocity of block A is 1 m/s but in the other direction

Answer 4

in wich class r u in?