UConn Phys. 1201 Final Exam
You must select which 8 problems you wish to be graded. You may have a formula sheet and the conversion table for this exam.
1. Points A – E, on the Displacement v. Time above graph, represent moments in time. Choose from the following phrases to describe what is occurring at each point in time.
1. Constant Velocity in the Positive X direction.
2. Zero Velocity
3. Acceleration in the negative X direction
4. Constant Velocity in the negative X direction
5. Acceleration in the Positive X direction.
A. ______B______C. ______D. ______E. ______
2. Derive an expression for the tension in the massless rope that connects the two masses, in terms of F, M1, and M2.
3. A projectile is fired at t=0 from the edge of the cliff as shown above. If the initial velocity of the projectile in the X and Y directions are Vy=200 m/s and Vx=20 m/s, and it lands at point P 50 seconds after it’s firing, what is the height (H) of the cliff?
4. At what distance from the center of the Earth should an astronaut be placed so that the astronaut will feel no net force from the Earth and Moon – given that the Earth, Moon and the astronaut are on the same line. Necessaryinformation:Mearth=5.97x1024kg,Mmoon=7.35x1022kg,G=6.67x10-11Nm2/kg,and the distancebetweencentersofearthandmoon=3.84x105km.
5. A 0.140 kg baseball is thrown toward the batter at 26.2 m/s. It is stuck by the bat with an average force of 5000N, which results in a velocity of 37.0 m/s in the opposite direction. How long were the ball and bat in contact? Assume that during this contact time, that the batter does not exert any force on the bat.
6.Amasslessspringhangsfromtheceiling.A28.8kgmassisattachedtotheendofthespringandthemassisreleased,sothatthemassstretchesthespring until it is in equilibrium. Howmuchdoesthepotentialenergyofthespringincreaseduetothemasswhenthehanging massismotionlessandatrest?Thespringconstantis4800N/m.
Hint: The force to stretch spring is F=k x where k is the spring constant and the work to stretch the spring is equal to the area under the Force v. Stretch graph shown below.
7. A 5.9 kg solid sphere is mad of a metal whose density is 3600 kg/m3. The sphere floats when placed ina liquid of density equal to 3800 kg/m3. What is the fraction of the volume of the sphere that is submerged?
8. A13gbulletpiercesasandbagwhich is 32cmthick. Ifthe bulletenters the bag with a velocityof68m/secanditemergesfromthesandbagwithavelocityof18m/sec,what wastheaveragefrictionalforce thatthebulletexperiencedwhileitwas travellingthroughthebag?
9. The graph below shows the temperature of a substance that begins as a solid and is heated until it is a vapor. Assume that heat is continuously added to the substance at a constant rate. From the information on the graph, what is the ratio of the heat of Vaporization (Lv) to the Heat of Fusion (LF)?
10. The PV graph below describes a gas enclosed in a sealed, but expandable container (the piston of an engine). What is the net work done by the engine?
b. If the engine repeats this cycle 5 times every second, what is the power output of the engine?