1. Construct freebody diagrams for the following physical situations.
a. A ball is dropped from rest from the top of a
building. Assume negligible air resistance. b. After being thrown, a football is moving upwards and
rightwards towards the peak of its trajectory. Assume
negligible air resistance. c. After reaching a terminal velocity, a falling skydiver
then opens up the parachute. d. An air track glider is gliding to the right at
constant velocity. e. A car is skidding to a stop while traveling to the
right. f. A downward moving elevator (held by a cable) slows
down. g. A 25.0N force is applied at a 30degree angle to a
crate in order to accelerate it rightward across a rough,
horizontal surface. h. A picture hangs symmetrically by two wires oriented at
angles to the vertical. i. A large crate slowly accelerated down a steep and
rough inclined plane.
Express your understanding of concepts of force, acceleration, and motion by answering the following questions.
2. Which of the following are always true of an object that is at equilibrium? Include all that apply.
3. Which of the following are never true of an object that is at equilibrium? Include all that apply.
4. Big Bubba has a mass of 100 kg on the earth. What is Big Bubba's mass on the moon where the force of gravity is approximately 1/6th that of Earth's? ________ Explain or show your work.
5. Little Billie weight 360 N on Earth. What is Little Billie's mass on the moon where the force of gravity is approximately 1/6th that of Earth's? ________ Explain or show your work.
6. TRUE or FALSE:
An object which is moving rightward has a rightward force acting upon it.
7. How much net force is required to keep a 5kg object moving rightward with a constant velocity of 2 m/s? ________ Explain or show your work.
8. TRUE or FALSE:
For an object resting upon a nonaccelerating surface, the normal force is equal to the force of gravity.
9. An object rests upon an inclined plane. If the angle of incline is increased, then the normal force would _______ .
a. increase 
b. decrease 
c. remain the same 
10. Three pictures of equal weight (20 N) are hung by wires in three different orientations. In which orientation are the wires least likely to break? _______ Explain why.
11. A 50N force is applied at an angle of 30 degrees north of east. This would be the same as applying two forces at
12. Which one(s) of the following force diagrams depict an object moving to the right with constant speed? Write all possible answers (if any) in the blank: ________________
Explain your answer(s) to this question.
Use the approximation that g=10 m/s^{2} to fill in the blanks in the following diagrams.
13.

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16. 
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22. A 945kg car traveling rightward at 22.6 m/s slams on the brakes and skids to a stop (with locked wheels). If the coefficient of friction between tires and road is 0.972, determine the distance required to stop. PSYW
23. A student pulls a 2kg backpack across the ice (assume frictionless) by pulling at a 30° angle to the horizontal. The velocitytime graph for the motion is shown. Perform a careful analysis of the situation and determine the applied force. PSYW
24. After its most recent delivery, the infamous stork announces the good news. If the sign has a mass of 10 kg, then what is the tensional force in each cable?
25. Splash Mountain at Disney World in Orlando, Florida is the steepest water plume ride in the country. Occupants of the boat fall from a height of 100 feet (3.2 ft = 1 m) down a wet ramp which makes a 45° angle with the horizontal. Consider the mass of the boat and its occupants to be 1500 kg. The coefficient of friction between the boat and the ramp is 0.10. Determine the frictional force, the acceleration, the distance traveled along the incline, and the final velocity of the boat at the bottom of the incline. PSYW
26. At last year's Homecoming Pep Rally, Trudy U. Skool (attempting to generate a little excitement) slid down a 42° incline from the GBS dome to the courtyard below. The coefficient of friction between Trudy's jeans and the incline was 0.650. Determine Trudy's acceleration along the incline. Begin with a freebody diagram. PSYW
27. Baldwin Young is conducting his famous toupee experiments. He tips his head at a given angle and determines the coefficient of static and kinetic friction between a toupee (which is probably his own) and his scalp. At an angle of just barely 17.5 degrees, the toupee begins to accelerate from rest. Then Baldwin lowers the angle to 13.8 degrees to observe that the toupee moves with a constant speed. Use this information to determine the coefficients of both static and kinetic friction. Begin with a freebody diagram. PSYW
28. Consider the twobody system at the right. There is a 0.250kg object accelerating across a rough surface. The sliding object is attached by a string to a 0.10 kg object which is suspended over a pulley. The coefficient of kinetic friction is 0.183. Calculate the acceleration of the block and the tension in the string. PSYW
29. Consider the twobody system at the right. A 22.7N block is placed upon an inclined plane which is inclined at a 17.2° angle. The block is attached by a string to a 34.5N block which is suspended over a pulley. The coefficient of friction is 0.219. Determine the acceleration of the block and the tension in the string. PSYW
30. Determine the time it will take the mass to fall a distance of 1.5 meters if starting from rest. (No friction)
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Last update: 5/2/02