



Unit 5 Quiz#1Equations:
1. Ben Travlun applies a vertical force to carry a 20kg suitcase at constant speed up four flights of stairs (a height of 15.0 m) and then pushes it with a horizontal force of 40.0 N at a constant speed of 0.75 m/s for a horizontal distance of 20.0 meters. How much total work does Ben do on his suitcase during this entire motion (which consists of two parts)? PSYW
Construct a freebody diagram (showing the direction and types of forces) for the suitcase being pushed across the floor at a constant speed of 0.75 m/s. Determine the magnitude of all forces and the coefficient of friction between the suitcase wheels and the floor. PSYW
2. In the "Its All Uphill" Lab, Amanda B. Reckenwyth applied a 15N force to a 3kg cart in order to pull it a distance of 2.0 m along the incline to a final height of 1.0 m. The velocity of the cart was a constant value of 0.25 m/s. Use this information to determine the work which Amanda does upon the cart. See diagram if necessary. PSYW EC: Determine the time required to pull the cart to the final height. PSYW
3. If the unit of mass is the lump, and the unit of time is the thump, and the unit of distance is the jump, then perform some unit analysis to express the unit of work in terms of lumps, thumps, and jumps.
4. An escalator is used to move 20 passengers every minute from the first floor of a department store to the second. The second floor is located 5meters above the first floor. The average mass of the passengers is 60 kg. Determine the power requirement of the escalator in order to move this number of passengers in this amount of time. Please organize and show all your work to maximize credit.
5. In her last crowdpleasing moment, Missy deWater (the former platform diver of the Ringling Brothers' Circus) dove from a platform and freefell towards a shallow bucket of water (see diagram). Missy's mass was 50 kg. a. Construct a freebody diagram, showing the force(s) acting upon Missy as she is falling from the platform. Label the force(s) to indicate their type. Assume no air resistance.
b.Identify the force(s) above as being either external or internal forces.
c. Does/do the above force(s) change Missy's total mechanical energy? Explain.
d. Fill in the blanks in the diagram at the right.
e. State Missy's acceleration as she is falling from the platform.
f. Calculate Missy's speed the moment before she hits the water (or in this case, the ground). PSYW
g. Determine the height of the platform from which Missy (m=50 kg) dove. PSYW
© Tom Henderson, 19961998 Last updated on
12/14/98. 