Posted by Ashley on Wednesday, February 3, 2010 at 9:35pm.
A 0.0600 kg tennis ball, moving with a speed of 2.50 m/s, has a headon collision with a 0.0900 kg ball initially moving away from it at a speed of 1.00 m/s. Assuming a perfectly elastic collision, what is the speed and direction of each ball after the collision?
I was given that the answer for the speeds of the balls are .70m/s and 2.2m/s.
equations:
m1v1+m2v2 = m1v1'+m2v2'
V1V2=V2'  V1'
My attempt:
with the given, I know that
m1= .06 kg
m2=.09 kg
v1= 2.5 m/s
v2= 1.0 m/s
after this, I got to .135=m1v1'+m2v2'
and 1.5= V2'V1'

Physics  bobpursley, Wednesday, February 3, 2010 at 10:03pm
I agree with this
m1v1+m2v2 = m1v1'+m2v2'
I disagree with this:
V1V2=V2'V1'
where in the world did that come from?

Physics  Ashley, Wednesday, February 3, 2010 at 10:08pm
I asked someone else for help on this problem and they told me to use that equation. That's even what they wrote down for me. I agree it doesn't make sense.
Anyways the initial and final mass will stay the same right? So I will be at...
135=(.06)v1'+(.09)v2'

Physics  bobpursley, Wednesday, February 3, 2010 at 10:25pm
Now you have one other equation you can use, the magic equation conservation of energy is true
Intial KE= final KE
You know initial KE. Final ke, 1/2 m1*V1'^2 + 1/2 m2 v2'^2 is equal to that initial.
Now, in your 135=(.06)v1'+(.09)v2'
solve for v2' in terms of all the other stuff, then put that v2' into the conservationof energy equation (yes square v2') It is messy algebra, you will get a quadratic you can solve (quadratic equation).
Answer This Question
Related Questions
 physics  A 0.060 kg tennis ball, moving with a speed 2.50 m/s, collides head on...
 physics collision  A 0.060 kg tennis ball, moving with a speed of 7.00 m/s has ...
 UPhys  A 0.060kg tennis ball, moving with a speed of 5.8m/s, has a headon ...
 physics  a billiard ball rolling across a table at 1.50m/s makes a head on ...
 physics  A ball of mass 0.440 kg moving east (+x direction) with a speed of 3....
 Physics  A ball of mass 0.640 kg moving east (+x direction) with a speed of 3....
 Physics  Assume a perfectly elastic collision between a 916g bat and a 145g ...
 Physics  A ball of mass 0.640 kg moving east (+x direction) with a speed of 3....
 Physics  Problem 3 A 10g metal ball is moving to the left with a velocity of ...
 phy  A ball of mass 0.540 kg moving east (+x direction) with a speed of 3.30 m/...
More Related Questions