Mapat Sapling Learning macmillan learning Nate the Skate was an avid physics stu
ID: 1585135 • Letter: M
Question
Mapat Sapling Learning macmillan learning Nate the Skate was an avid physics student whose main non-physics interest in life was high-speed skateboarding. In particular, Nate would often don a protective suit of Bounce-Tex, which he invented, and after working up a high speed onhis skateboard, would collide with some object. In this way, he got a gut feel for the physical properties of collisions and succeeded in combining his two passions. On one occasion, the Skate, with a mass of 113 kg, including his armor, hurled himself against a 803-kg stationary statue of Isaac Newton in a perfectly elastic linear collision. As a result, Isaac started moving at 1.21 m/s and Nate bounced backward. What were Nate's speeds immediately before and after the collision? (Enter positive numbers.) Ignore friction with the ground. Before: Number m/s After: Number m/s By the way, this brief bio of Nate the Skate is written in the past tense, because not long ago he forgot to put on his Bounce-Tex before colliding with the Washington Monument in a perfectly inelastic collision. We will miss him.Explanation / Answer
Here you can use the assumption of conservation of momentum to solve the problems.
Means -
M×U + M×U = M×V + M×V
and
U - U = V - V
as mentioned in the problem -
M = mass 1 = 113 kg
M = mass 2 = 803 kg
U = speed of mass 1 before collision = ?
U = speed of mass 2 before collision = 0 m/s
V = speed of mass 1 after collision = ?
V = speed of mass 2 before collision = 1.21 m/s
therefore -
113×U + 803×0 = 113×V + 803×1.21
113×U = 113×V + 971.63 ----------------------------------------(i)
and
U - 0 = 1.21 - V
U = 1.21 - V ---------------------------------------(ii)
substitute (ii) in (i) -
113×(1.21 - V) = 113×V + 971.63
136.73 - 113×V = 113×V + 971.63
-834.9 = 226×V
V = - 834.9 / 226 = -3.69 m/s
substitute that value in (ii) -
U = 1.21 - (- 3.69)
U = 4.90 m/s
Therefore -
Nate's speed immediately before the collision is 4.90 m/s means in forward direction.
Nate's speed immediately after the collision is - 3.69 m/s means in backward direction.