Nate the Skate was an avid physics student whose main non-physics interest in li

Question

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 on his 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 123 kg, including his armor, hurled himself against a 821-kg stationary statue of Isaac Newton in a perfectly elastic linear collision. As a result, Isaac started moving at 1.43 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:

A- Before??

B- After??

Explanation / Answer

We need two formula's for solving this kind of problems

M1×U1 + M2×U2 = M1×V1 + M2×V2

and

U1 - U2 = V2 - V1

where

mass,m1=123 kg

mass of statue,m2=821-kg

velocity,v2=1.43 m/s

U1 = speed of mass 1 before collision = ?

U2 = speed of mass 2 before collision = 0 m/s

V1 = speed of mass 1 after collision = ?

so

123×U1 + 821×0 = 123×V1 + 821×1.43

123×U1 = 123×V1 + 1174----------------------(equation 1)

and

U1- 0 = 1.43 - V1

U1= 1.43 - V1 --------------- (equation 2)

substitute (equation 2) in (equation 1)

123×(1.43 - V1) = 123×V1 + 1174

175.89 - 123×V1 = 123×V1 + 1174

-998.11 = 246×V1

V1 = - 4.05 m/s

substitute that value in (equation 2)

U1 = 1.43 - (- 4.05)

U1 = 5.48 m/s

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.