University Physics Lab 1 Flashcards

Disk # Diameter (D) (cm) Circumference (C) (cm) (Pi) =C/D

1 1.268±0.002 4.0±0.1 3.15±0.08

1 1.266±0.002 4.1±0.1 3.24±0.08

5 25.3 ±0.1 79.7 ±10.2 3.15 ±0.01

5 25.4 ±0.1 79.6 ±0.2 3.13 ±0.01

1. Which disk measurements (1 or 5) provide a more precise determination of pi and why?
A. Disk 1 because we could use the Vernier calipers on the diameter measurement.
B. Disk 1 because it is smaller and more manageable.
C. Disk 5 because we got closer to the actual value of (pi).
D. Disk 5 because both precision errors, on C and D, are a small fraction of the measurements.

2. Including the rest of the disk measurements, we then get an average of (pi) = 3.149±0.008. What should we conclude from this?

A. Our determination disagrees with the accepted value of (pi), since 3.149±3.14159...

B. Our determination disagrees with the accepted value of (pi), not within the precision error.

C. Our determination agrees with the accepted value of (pi), since the precision and accuracy are comparable and reasonably small.

D. It is difficult to conclude anything from the uncertainties involved.

3. For the Graph Matching lab today, what kind of sensor will we be using to take data?
A. A stopwatch timer.

B. A motion detector.

C. A photogate timer.

D. A video camera.

4. What object will we be measuring the motion of?
A. You!
B. A swinging pendulum.

C. A rolling chair,

D. A falling object.

5. During the first 4 seconds, what is true about the acceleration?

A. It is constant

B. It is increasing at a constant rate

C. It is increasing at a variable rate

D. It is discontinuous

6. During the first 4 seconds, what is true about the distance?

A. It is constant

B. It is increasing at a constant rate

C.It is increasing at a variable rate

D. It is discontinuous

7. In the projectile motion lab we measure the initial velocity of the ball by:

A. Using a stopwatch to measure the time of fall and the measured horizontal distance.

B. Calculating it based on initial height and range when the ball is fired horizontally

C. Using a photogate timer

D. Using a motion sensor

8. The purpose of the projectile motion lab is to:

A. Predict and then verify the range of a projectile fired at an angle.

B. Measure and then calculate the range of a projectile fired at an angle.

C. Predict and then verify the range of a projectile fired horizontally.

D. Measure and then calculate the range of a projectile fired horizontally.

9. For last week's lab, we determined the initial velocity of the projectile by firing horizontally off the lab bench to the floor and measuring the average range. We collect data and find that from a launch height of h = 1.10 m the average range is 2.37 m. What is the launch velocity?

A. 4.63 m/s

B. 4.81 m/s

C. 4.90 m/s

D. 5.00 m/s

10. The precision of the projectile lab is based on:

A. how much spread there is in individual hits.

B. how close to the predicted range the measured range is.

C. how accurate the meter stick is.

D. all of the above.

11. Static friction is always identical to starting friction. True or False?

A. True

B. False

12. Kinetic friction is modeled as the coefficient of kinetic friction times the normal force. True or False?

A. True

B. False

13. The coupled system lab was designed to test Newton's 2nd Law. We found that the measured acceleration was____than the theoretical acceleration (mh *g/(mh + mc)), primarily due to____.

A. much less, friction and air resistance

B. a few percent less, rolling friction

C. a few percent more, rolling friction

D. much greater, friction and air resistance

14. For a hanging mass of 70g with a downwards acceleration of 1.40 m/s, we find that the measured tension in the string is:

A. 0.59 N

B. 0.69 N

C. 0.78 N

D. 5.9 N

E. 6.9 N

F. 7.8 N

15. For lab this week we will investigate work and energy. In order to raise a mass up at a constant speed, the applied force must be ____ its weight.

A. less than

B. equal to

C. greater than

16. For lab we will investigate how work done is equivalent to:

A. absolute potential energy

B. absolute kinetic energy

C. changes in either potential or kinetic energies

17. The above graph shows force vs. height as a mass is being raised. The starting height at the left edge of the shaded area is 0.60 m. The ending height at the right edge of the shaded area is 1.50 m. If the average force is 2.00 N, what is the work done in raising the mass?

A. 1.20 J

B. 1.80 J

C. 2.22J

D. 3.00 J

E. Need to know the mass

18 . A cart with mass 1.5 kg is accelerated by a force whose average value is 3.24 N. The cart starts at rest and has a final speed of 1.1 m/s. For what distance did the force act?

A. 0.23 m

B. 0.28 m

C. 0.65 m

D. 0.71 m

E. 0.83 m

F. 0.91 m

19. For a vertical oscillating mass on a spring, its height vs time and its velocity vs time:

A. are moving up and down together in time.

B. are such that when one is maximum or minimum, the other is at its mid-point.
C. are exactly opposite such that when one is maximum the other is minimum.
D. are uncorrelated.

20. For this lab we will investigate energy in simple harmonic motion. We expect____to be conserved.

A. Kinetic Energy

B. Potential Energy

C. Total Mechanical Energy

D. All of the above

21. For a mass hanging from a vertical spring, which of the above curves represents the kinetic energy vs. time if the mass is released from rest below the equilibrium?

A. Solid Flat Line on Top

B. Dashed Curve

C. Solid Curve

D. Solid Flat Line Bottom

22. For a mass hanging from a vertical spring, which of the above curves represents the potential energy vs. time if the mass is released from rest below the equilibrium?

A. Solid Flat Line on Top

B. Dashed Curve

C. Solid Curve

D. Solid Flat Line Bottom

23. Which of the following types of collisions are not represented in the 3 parts of today's lab?

A. Elastic

B. Inelastic

C. Completely Inelastic

D. Super-Elastic

24. For this lab we will investigate momentum and energy in collisions. For all of the collisions we expect _____to be conserved.

A. Total Momentum

B. Total Mechanical Energy

C. Total Momentum and Total
Mechanical Energy

During the collision lab, the following measurements are taken:

m1 = 0.550 kg

vl before =3.27 m/s vl after = 0.45 m/s

m2 = 0.540 kg

v2 before = 0.0 m/s v2 after = 2.67 m/s

25. Which type of collision does this represent?

A. Elastic

B.Super-Elastic

C.Totally inelastic

D. Partially inelastic

26. Approximately how much of the initial mechanical energy is lost in the collision?

A. 0%

B. 33%

C. 50%

D. 100%

27. In a car collision, the driver's body changes speed from a high value to zero, with or without an airbag. So why use an airbag?

A. It reduces the impact force

B. It reduces the impact time

C. It gives less impulse

D. All of the above

28. You want to close an open door by throwing either a 100g lump of clay or a 100g rubber ball toward it. You can throw either object with the same speed, but they are different in that the rubber ball bounces off the door while the clay just sticks to the door. Which projectile will be more likely to close the door?

A. the clay

B. the rubber ball

C. both equally likely

29. For the ballistic pendulum last week the collision between the ball and the pendulum arm is

A. Totally inelastic

B. Partially inelastic

C. Elastic

D. Super-elastic

30. Approximately how much of the initial mechanical energy is lost in the collision?

A. 0%

B. 26%

C. 52%

D. 78%

E. 100%

31. In a car collision, the driver's body changes speed from a high value to zero, with or without an airbag. So why use an airbag?

A. It reduces the impact force

B. It reduces the impact time

C. It gives less impulse

D. All of the above

32. You want to close an open door by throwing either a 100g lump of clay or a 100g rubber ball toward it. You can throw either object with the same speed, but they are different in that the rubber ball bounces off the door while the clay just sticks to the door. Which projectile will be more likely to close the door?

A. the clay

B. the rubber ball

C. both equally likely

33. Which of the following impulses will change the velocity of an object the most?

A. Fave = 50.0N, At = 0.10 sec

B. Fave = 10.0N, At = 0.50 sec

C. Eave = 2.0N, At = 5.0 sec

D. Fave = 0.5N, At = 10.0 sec

34. What is the average force acting on a tennis ball by a tennis racket if the tennis ball (m = 0.070 kg) comes in at 30.0 m/s and returns in the opposite direction at 30.0 m/s and is in contact with the tennis racket for a total time of 0.010 sec?

A. 0! the speed is unchanged

B. 0.042 N

C. 210 N

D. 420 N

35. For lab this week, what type of collision is made between the ball and arm attached to the turntable?

A. Totally inelastic

B. Partially inelastic

C. Elastic

D. Super-elastic

36. What quantity (or quantities) will be conserved in the collision between the ball and the arm attached to the turntable?

A. Mechanical energy

B. Linear momentum

C. Angular momentum

D. All of these quantities