A brave stunt devil would like to recreate one of Evil Knievel’s famous jumps, launching himself and his bike across line of trucks which are arranged side by side, each of which is roughly 2.6 m wide. Strangely, he decides to do this by using a very stiff springboard, which is originally compressed by 1.5 m, to push the bike up a ramp which is inclined at an angle of 23° and is 3.0 m long from the edge of the springboard (see figure). Ignoring the effects of air resistance, suppose the stunt devil would like to jump 25 trucks, needing to reach a speed of about 30 m/s by the edge of the ramp.   a)  If the stunt devil and the bike have a combined mass of 160 kg, what must the spring constant of the springboard be in order for the stunt devil to make the jump if the ramp is effectively frictionless? b)  What total work must be done on the stunt devil for him to make the jump? Which forces do work as he moves along the ramp? c)  Suppose the ramp does provide a small frictional force on the tires of the bike, doing -3,000 J of work on the stunt devil as he reaches the edge of the ramp. By how much further should the spring be compressed for the stunt devil to safely make the jump? d)  If the springboard of part c) is in contact with the stunt devil for about 1.8 s, what average Power does the spring deliver to the stunt devil?

Lightning McQueen rounds a curve of radius 80 m which is banked so that cars traveling at 100 km/hr (27.8 m/s) can safely take the curve even in the absence of friction. The coefficient of static friction between Lightning McQueen’s tires and the road is 0.72.     a)   Draw a FBD of Lightning McQueen as he rounds the curve, assuming he does so without slipping. b)   At what angle is the curve banked?  c)   What is the maximum speed with which Lightning McQueen can take the curve without skidding?

Two ladybugs land on a vinyl record of radius R = 15 cm which is initially at rest.  The first ladybug lands halfway from the center of the disc, while the other lands on its edge as shown below. The disc then begins to rotate, speeding up with an angular acceleration given by

When a rigid object rotates about a fixed axis, what is true about all the points in the object?

An piece of space debris is released from rest at an altitude that is two earth radii from the center of the earth. Compared to its weight on Earth, the weight of this debris is

When an object moves in non-uniform circular motion, the direction of its acceleration vector

A constant force 

A particle moves in a straight line under the influence of a force

An object is moving in a straight line with a varying velocity given by 

Sonic the Hedgehog, of mass 42 kg, leaps onto a Jump Spring in order to make it to a platform in front of him that is 3.5 m above his head. The spring is angled at 27° with respect to the ground, and Sonic compresses the spring by 1.7 m from its uncompressed length after jumping on it.      a)  If Sonic leaves the Jump Spring when it is fully uncompressed travelling at 30 m/s, what was the spring constant of the spring? b)  What is the maximum height reached by Sonic, neglecting the effects of air resistance or drag? c)  If Sonic begins to skid as he lands, sliding a horizontal distance of 7.7 m before coming to rest, what is the coefficient of kinetic friction between Sonic and the platform?