Part A Find the magnitude of the velocity of the red puck after the collision. E
ID: 1990950 • Letter: P
Question
Part A Find the magnitude of the velocity of the red puck after the collision. Express your answer using two significant figures. Part A Find the magnitude of the velocity of the red puck after the collision. Express your answer using two significant figures. Part A Find the magnitude of the velocity of the red puck after the collision. Express your answer using two significant figures. Part B Find the direction of the velocity of the red puck after the collision. Part B Find the direction of the velocity of the red puck after the collision. Part B Find the direction of the velocity of the red puck after the collision. Part C Express your answer using two significant figures.=
Explanation / Answer
Using the law of conservation of momentum
M1V1 + M2V2 = M1V3 + M2V4
where
M1 = mass of the blue puck = 0.038 kg.
V1 = initial velocity of the blue puck = 0.250 m/sec.
M2 = mass of the red puck
V2 = initial velocity of the red puck = 0 (at rest)
V3 = final velocity of the blue pack = 0.080 m/sec.
V4 = final velocity of the red puck
Substituting values,
0.038(0.250) + 0 = 0.038(.08) + (M2)(V4)
(M2)(V4) = 0.00646 --- call this Equation 1
Since the kinetic energy is conserved,
(1/2)(.038)(.25)^2 = (1/2)(0.038)(.08)^2 + (1/2)(M2)(V4)^2
(M2)(V4)^2 = 0.00228
The above can be rewritten as
(M2*V4)(V4) = 0.0021318
Since (M2*V4) = 0.00646(from Equation 1), then
0.00646(V4) = 0.0021318
and solving for "V4"
V4 = 0.33 m/sec
Since the velocity calculated above is positive, then the direction of the red puck is the same as the direction of the blue pack after collision.
From Equation 1,
M2 = 0.00646/0.33
M2 = 0.0196 kg.