Final Exam Review
Supplemental Instruction
Iowa State University / Leader: / Wesley Hutter
Course: / PHYS 221
Instructor: / Canfield/Herrera-Siklody
Date: / 12/12/2013
  1. Superman begins to spin a playground merry-go-round. The angular acceleration of a playground roundabout with radius r = 3 m is given by the equation below.

What is the magnitude of the acceleration of Klyde, a young man who is hanging on for dear life at the edge of the merry-go-round at time t = 2.00 s, if the wheel is at rest at t = 0.00 s?

  1. 102 m/s2
  2. 527 m/s2
  3. 972 m/s2
  4. 977 m/s2
  5. 1070 m/s2
  6. Superman would never do such a thing.
  1. A 2.50-kg block is placed on top of a 4.00-kg block. The coefficients of friction between them are μk = 0.300 and μs = 0.400. The whole system is on a frictionless, horizontal table. A horizontal force F = 15.0 N is applied to the bottom block. What is the magnitude of the friction force between two blocks?
  1. 9.81 N
  2. 8.59 N
  3. 7.36 N
  4. 6.57 N
  5. 5.77 N
  6. I don’t know.

Important Practice: What would the answer be if F = 30 N? (The answer is one of the choices present in the question)

  1. A 1500-kg space station is in circular orbit around the earth. It has a period of 48 hours. What is the gravitational force that is acting on this space station?
  1. 1.33*102 N
  2. 1.47*104 N
  3. 6.71*107 N
  4. 8.92*109 N
  5. 9.38*1010 N
  6. 0 N because otherwise, everything wouldn’t be able to float around in the space station.
  1. A ride at a carnival slings passengers such as yourself in vertical circles in bucket-like compartmentswith open tops. The length of the arms that hold the buckets 50 m, the mass of the bucket is 200 kg, and your mass is about 70 kg. You can neglect the weight of the arm that is holding the bucket. What is the minimum speed that the mass needs while it is traveling directly upward (i.e. when it is on the right of a path of motion that is a circle moving in a counterclockwise direction), if you are to stay in the bucket on the ride?
  1. 22.1 m/s
  2. 31.3 m/s
  3. 38.4 m/s
  4. 44.3 m/s
  5. 49.5 m/s
  6. I need to go to Six Flags to do further research before I can solve this problem.
  1. Your little cousin Throckmorton has found himself trapped in the refrigerator at a chilly temperature of 5 ºC. Before you find him, he happens to find an empty steel cup of volume 400 cm3. Somehow, he is able to pour himself an incredibly full cup of apple juice in his cramped quarters. Just as he is about to take a sip, you find him, and everyone is so excited about finding him (including Throckmorton himself) that his full cup of juice is left on the counter in a room of 25ºC. If the volumetric expansion coefficients of the steel cup and the apple juice are 3.6*10-5 K-1 and 2.14*10-4 K-1 respectively, how much apple juice overflows out of the cup?
  1. .973 cm3
  2. .995 cm3
  3. 1.00 cm3
  4. 1.24 cm3
  5. 1.47cm3
  6. I’m just glad that I found my favorite cousin, Throckmorton!
  1. Two thermally insulated containers are filled with an ideal monatomic gas and an ideal diatomic gas, respectively. Both gases are initially at temperature P0and each one occupies a volume of V0. The gas in each container expands adiabatically to a final volume of 2V0. What is the ratio of the two gases’ final pressures, ?

A.0.27

B.0.83

C.1.0

D.1.5

E.2.2

F.Physics is difficult.

  1. You have just come into your friend, Bartholomew’s, warm house from the cold. To greet him, you immediately place your hand of temperature 0 degrees C on his cheek, which is a temperature of 30 degrees C. Bartholomew is silly enough to let you keep your hand there until your hand and his cheek reach thermal equilibrium at 15 degrees C. You can assume that the effective mass of both your hand and his cheek are 0.5 kg, the effective specific heat of human flesh is 3470 J/kg-K, and you can assume that heat only flows between your hand and his cheek. What is the change in entropy for this system?
  1. -88.1 J/K
  2. -4.71 J/K
  3. 0.00 J/K
  4. 4.71 J/K
  5. 92.8 J/K
  6. Bartholomew is silly. It’s no fun if he doesn’t squirm.
  1. An image of a dam holding back a certain amount of water is shown here below. In order to construct a dam of this nature, it must be known what kind of forces static water will exert on it, due to static fluid pressure. In this scenario, the height of the water is 200 m, and the width of the damn (dimension into the page) is also 200 m. If the pressure of the static fluid is equal to ρgh at the bottom of the dam, what would be the force per infinitesimal unit height (F/dx)acting on the dam at a point 50.0 m from the bottom of the dam?
  1. 1.96*106 N/m
  2. 1.53*107 N/m
  3. 2.76*107 N/m
  4. 2.94*108 N/m
  5. 3.92*108 N/m
  6. As a civil engineer, when people say,“Dam it!” I say, “Hey! I can do that!”
  1. At a carnival, there is a game in which you are required to knock down a very heavy bowling pin with a ball. However, at this particular station, they allow you to choose between a bouncy ball that will bounce back off of the pin once it hits, and a sticky ball that will stick to the pin after it hits. Both balls have the same mass. Which ball should you choose, and why?
  1. The sticky ball because the velocity transferred back to the bouncy ball will be taken away from the potential velocity the pin would have had after being stricken
  2. The sticky ball because the weight of the ball will offset the pin’s center of gravity, and make it more likely to tip.
  3. The bouncy ball because the impulse on the bouncy ball is greater than that of the impulse that would have been done on the sticky ball.
  4. The bouncy ball because all of the ball’s velocity will be transferred to the pin.
  5. It does not matter which ball is chosen; they are equally likely to knock the pin over.
  6. It does not matter which ball is chosen because I will definitely miss the pin anyway.
  1. The drawing shown here is an example of an Atwood’s machine. In this particular drawing, m = 4 kg, and M = 9 kg, and the two hanging masses are released from rest. The pulley is a cylinder whose mass is NOT equally distributed, and thus its moment of inertia is equal to , when R is the radius of pulley. What is the magnitude of the acceleration of the two blocks?
  1. 2.38 m/s2
  2. 2.62 m/s2
  3. 7.13 m/s2
  4. 7.85 m/s2
  5. 9.810 m/s2
  6. I’ll get back to you after I ask Dr. Canfield for the answer.
  1. (Bonus Question) You have a stopped pipe of adjustable length close to a taut 1-m, 10-g wire under a tension of 5000 N. You want to adjust the length of the pipe so that when it produces sound at its fundamental frequency, it causes the wire to vibrate in its first overtone with very large amplitude. How long should the pipe be?
  1. 8.11 cm
  2. 12.2 cm
  3. 24.3 cm
  4. 43.0 cm
  5. 86.0 cm
  6. It doesn’t matter how long the pipe is because I DON’T CARE.
  1. The figure here shows the setup used in the experiment for free oscillations. The maximum force is measured to be 30 N, the total distance of oscillation is 1.0 m, and the distance from the motion detector to the equilibrium position of oscillation is approximately 2.0 m. What will the motion detector read when the force is at a minimum, and what will it read when the force is at its maximum reading of 30 N?
  1. Fmax = 1.5 m, Fmin = 2.5 m
  2. Fmax. = 1.0 m, Fmin = 3.0 m
  3. Fmax. = 0.0 m, Fmin = 1.0 m
  4. Fmax. = 0.0 m, Fmin = 0.5 m
  5. Fmax. = 2.0 m, Fmin = 3.0 m
  6. I don’t know because my lab partner did all the work for me.