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1. Watch this video clip (http://physics.info/energy-conservation/slide-spiderma

ID: 1500074 • Letter: 1

Question

1. Watch this video clip (http://physics.info/energy-conservation/slide-spiderman.html) before beginning this problem. The height of the building Spider-Man (a.k.a. Peter Parker, a.k.a. Tobey McGuire) starts off on is 6 stories, or 18 meters high (assuming one story is 3 meters).The height of the building he wants to swing to is 1 story, or 3 meters high. The crane onto which he shoots his web is 7 stories, or 21 meters high. Tobey McGuire is 1.75 m tall and approximately 72 kg in mass. (Do not use the equations of motion to solve any part of this problem.) Determine…

a. Spider-Man's speed when his feet touch the roof the second building

b. The approximate kinetic energy dissipated when Spider-Man struck the wall

Explanation / Answer

a)   Loss in gravitational potential energy = Gain in kinetic energy

=> 72 * 9.8 * (18 - 3 )   = 1/2 * 72 * v2

=>    v   =   17.146 m/sec              -------------------->   Spider-Man's speed when his feet touch the roof

b)   approximate kinetic energy dissipated = 1/2 * 72 * (17.146)2

                                                                                                 =   10584 J