Science
posted by nammilee_2012 .
A 0.500 kg ice puck, moving east with a speed of 3.30 m/s, has a headon collision with a 0.900 kg puck initially at rest. Assuming a perfectly elastic collision, (a) what will be the speed of the 0.500 kg object after the collision? (b) What will be the speed of the 0.900 kg object after the collision?

Science 
nammilee_2012
Suppose,
The velocity of .5 kg ice puck before collision = u1= 3.30 m/s
The velocity of .9 kg ice puck before collision = u2= 0
The velocity of .5 kg ice puck after collision = v1=?
The velocity of .9 kg ice puck after collision = v2=?
According to conservation of momentum,
m1u1 + m2u2 = m1v1 + m2v2
=> (u1v1)m1 = (v2u2)m2 ....(i)
Again, conservation of energy gives
1/2 m1u1^2+ 1/2 m2u2^2 = 1/2 m1v1^2 + 1/2 m2v2^2
=> m1(u1^2  v1^2) = m2(v2^2  u2^2) .....(ii)
Divide (ii) by (i)
(u1^2  v1^2)/(u1v1) = (v2^2  u2^2)/(v2u2)
=> u1+v1 = v2+u2
=> v1= u2+v2u1 = v2u1 ....(iii). [u2=0]
Now, substitute v1 in (i)
(u1v2+u1)m1 = (v2u2)m2
=> 2m1u1  m1v2 = m2v2
=> (m1+m2)v2 = 2m1u1
=> v2 = (2m1u1)/(m1+m2) ....(iv)
Substitute v2 in (iii)
v1= v2u1 = (2m1u1)/(m1+m2) u1
=> v1 = (2*.5*3.30)/(.5+.9)  3.30 = 2.357  3.30 = 0.943 m/s
() sign indicates that the ice puck is moving to the west.
Now substitute v1 in (iii) again
v1 = v2u1
=> v2 = u1+v1 = 3.30  0.943 = 2.36 m/s
It means it is going to the east. 
Science 
Elena
Correct answers.
http://hyperphysics.phyastr.gsu.edu/hbase/elacol2.html#c3
Respond to this Question
Similar Questions

PHYSICS
A 0.445 kg ice puck, moving east with a speed of 2.82 m/s, has a headon collision with a 0.918 kg puck initially at rest. Assuming a perfectly elastic collision, what will be the speed and direction of each object after the collision? 
Physics
A 0.490 kg hockey puck, moving east with a speed of 5.80 m/s, has a headon collision with a 0.870 kg puck initially at rest. Assume a perfectly elastic collision. (Let east be the +x direction.) (a) What will be the speed of each … 
physics
A 0.500 ice puck, moving east with a speed of 6.70 , has a headon collision with a 0.700 puck initially at rest. Assuming a perfectly elastic collision, what will be the speed of the 0.500 object after the collision? 
Physics
An elastic collision occurs between two pucks on an airhockey table. Puck A has a mass of 0.025 kg and is moving along the x axis with a velocity of +5.5 m/s. It makes a collision with puck B, which has a mass of 0.060 kg and is initially … 
Physics
A 0.300kg ice puck, moving east with a speed of 5.86m/s , has a headon collision with a 0.990kg puck initially at rest. Assume that the collision is perfectly elastic. What is the speed of the 0.300kg puck after the collision? 
physics
A 0.300kg ice puck, moving east with a speed of 5.86m/s , has a headon collision with a 0.990kg puck initially at rest. Assume that the collision is perfectly elastic. What is the speed of the 0.300kg puck after the collision? 
College Physics
A 0.300kg ice puck, moving east with a speed of 5.86m/s , has a headon collision with a 0.990kg puck initially at rest. Assume that the collision is perfectly elastic. What is the speed of the 0.300kg puck after the collision? 
Physics
A 0.250kg ice puck, moving east with a speed of 5.26m/s , has a headon collision with a 0.990kg puck initially at rest. Assume that the collision is perfectly elastic.What is the speed of the 0.250kg puck after the collision? 
physics
A 0.400kg ice puck, moving east with a speed of 5.38 m/s , has a headon collision with a 0.950kg puck initially at rest. Assume that the collision is perfectly elastic. What is the speed of the 0.400kg puck after the collision? 
Physics
A 0.471kg hockey puck, moving east with a speed of 8.17 m/s, has a headon collision with a 0.795kg puck initially at rest. Assuming a perfectly elastic collision, what will be the speed of the 0.795kg puck after the collision?