- (3 pts) Suppose a car is travelling north and skidding to a stop on level pavement, what is the reaction force to the friction force on the car? Be sure to state what object is exerting the reaction force, what object the reaction force acts on, and what direction the reaction force acts.
- (3 pts) Suppose a car is travelling north and skidding to a stop on level pavement, what is the reaction force to the normal force on the car? Be sure to state what object is exerting the reaction force, what object the reaction force acts on, and what direction the reaction force acts.
- (3 pts) A 95 kg bicyclist is travelling at a constant speed of 25.0 m/s down a 30.0 degree incline. At what rate is the gravitational force doing work on the bicyclist?
- (3 pts) Consider the toy car traveling around the circular track shown below. If the normal force that acts on the car at the bottom of the loop is equal to twice the weight of the car, then the magnitude of the acceleration of the car at that point is:
a) g
b) 2g
c) 3g
d) None of the above
e) Can not be determined without additional information
- (12 pts) Two strings hold the cube shown in place. The tension in string 2 is measured to be 5.00 N. Determine the weight of the cube and the tension in string 1.
- (12 pts) Suppose a car is travelling down a 30.0 degree incline and skidding to a stop. The car has a mass of 1.0 * 10^3 kg. The car skids 15.0 m as it slows from 20.0 m/s to 12 m/s. How much work is done on the car by the force of friction as it skids those 15.0 m?
- (12 pts) A triangular wedge with mass 6.00 kg is placed on the floor of an elevator. A block with mass 1.5 kg is placed on the wedge. There is sufficient static friction that the block does not slide on the wedge. If the elevator is travelling downward and slowing down at a rate fo 3.00 m/s^2, what is the magnitude of each force which acts on the cube?
- (12 pts) A spring is used to project a block with a mass of 80.00 g around a frictionless loop track. The circular portion of the track has a radius of 20.0 cm. A sensor at the top of the track is used to measure the magnitude of the normal force on the block. When the block is released with the spring compressed by 10.0 cm, the block makes it around the loop and the force sensor measures 0.6 N. Determine the force constant of the spring.
