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 113 kg, including his armor, hurled himself against a 805-kg stationary statue of Isaac Newton in a perfectly elastic linear collision. As a result, Isaac started moving at 1.93 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: before= ? m/s PLEASE DO NOT ROUND after= ? m/s please do not round PLEASE DO NOT ROUND ANY NUMBERS. THANKS!

Explanation / Answer

Key concept : momentum & energy conservation

Pi = Pf ( take right as positive )

113* u +0 = 805 * 1.93 + 113 * v ..............1

u = ( 805 * 1.93 + 113 * v) / 113

energy conservation

KE+UEi = KE+UEf

KEi = KEf

1/2* 113*u^2 +0 = 1/2* 805*1.93^2 + 1/2* 113*v^2

put u value here

0.5* 113 *[ ( 805 * 1.93 + 113 * v) / 113]^2 = 1/2* 805*1.93^2 + 1/2* 113*v^2

solve this

we got   

v = 5.90956 m/s after impact in left direction

u = ( 805 * 1.93 + 113 * 5.90956) / 113

=19.658675 m/s before impact

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

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