- #1
cherioslover
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Homework Statement
Two 0.3 Kg gliders collide elastically on a frictionless track. Prior to the collision , their total kinetic energy is 0.52 J and their total momentum is 0.12 Kg m/s
along the track. Calculate the final velocities of the gliders.
m1vi1 + m2vi2 = m1vf1 + m2vf2
1/2m1vi1^2 + 1/2m2vi2^2 = 1/2m1vf1^2 + 1/2m2vf2^2
tried subbing into conservation of momentum equation, and the conservation of energy formula, then subbing 1 into 2 to find final velocities, but its not working. Can someone tell me what I am doing wrong or if the solution i am using is correct?
m1vi1 + m2vi2 = m1vf1 + m2vf2
-0.12 = (0.3)vf1 + (0.3)vf2
-0.4 = vf1 + vf2
-0.4 - vf2 = vf1
1/2m1vi1^2 + 1/2m2vi2^2 = 1/2m1vf1^2 + 1/2m2vf2^2
0.52 = (0.3)(vf1)^2 + (0.3)(vf2)^2
√(0.52/0.3) = vf1 + vf2
1.32= vf1 + vf2
sub 1 into 2
1.32 = -0.4 - vf2 + vf2
This is where i am confused, because vf2-vf2 is obviously 0. I know somethings not right, and some assistance would be kindly appreciated :) The answers if needed are supposed to be 1.5 m/s
Homework Equations
m1vi1 + m2vi2 = m1vf1 + m2vf2
1/2m1vi1^2 + 1/2m2vi2^2 = 1/2m1vf1^2 + 1/2m2vf2^2
The Attempt at a Solution
tried subbing into conservation of momentum equation, and the conservation of energy formula, then subbing 1 into 2 to find final velocities, but its not working. Can someone tell me what I am doing wrong or if the solution i am using is correct?
m1vi1 + m2vi2 = m1vf1 + m2vf2
-0.12 = (0.3)vf1 + (0.3)vf2
-0.4 = vf1 + vf2
-0.4 - vf2 = vf1
1/2m1vi1^2 + 1/2m2vi2^2 = 1/2m1vf1^2 + 1/2m2vf2^2
0.52 = (0.3)(vf1)^2 + (0.3)(vf2)^2
√(0.52/0.3) = vf1 + vf2
1.32= vf1 + vf2
sub 1 into 2
1.32 = -0.4 - vf2 + vf2
This is where i am confused, because vf2-vf2 is obviously 0. I know somethings not right, and some assistance would be kindly appreciated :) The answers if needed are supposed to be 1.5 m/s
and 1.1 m/s