its impulse it starts with is
mv=1.45 N. You know the mass of the ball, calculate its velocity. then, calculate its KEnergy.
Now you have two equations:
momentum
mv=mv1+mv2 unknowns v2, v1
energy
1/2 mv^2=1/2 mv1^2 + 1/2 mv2^2
so in equation 1, solve for v1 in terms of v2. then substitute all that for v1 in the second equation, and solve for v2 in the quadratic.
A cue ball (mass = 0.145 kg) is at rest on a frictionless pool table. The ball is hit dead center by a pool stick, which applies an impulse of +1.45 N · s to the ball. The ball then slides along the table and makes an elastic head-on collision with a second ball of equal mass that is initially at rest. Find the velocity of the second ball just after it is struck
2 answers
Too much work. ALL of the momentum must go to the second ball for perfectly elastic involving same masses(should be a give away that no info is provided post-collision).
FT = mv
1.45/.145 = v
You can verify quickly by making the velocity of the second 10 and the answer pops right out.
Mind you this only works if the masses are the same.
FT = mv
1.45/.145 = v
You can verify quickly by making the velocity of the second 10 and the answer pops right out.
Mind you this only works if the masses are the same.
2 answers