Last Name: First Name Net ID:
Discussion Section: Discussion TA Name:
Instructions—
Turn off your cell phone and put it away.
Calculators cannot be shared. Please keep yours on your own desk.
This is a closed book exam. You have sixty (60) minutes to complete it.
1. Use a #2 pencil; do not use a mechanical pencil or a pen. Fill in completely (until there is no white space visible) the circle for each intended input – both on the identification side of your answer sheet and on the side on which you mark your answers. If you decide to change an answer, erase vigorously; the scanner sometimes registers incompletely erased marks as intended answers; this can adversely affect your grade. Light marks or marks extending outside the circle may be read improperly by the scanner.
2. Print your last name in the YOUR LAST NAME boxes on your answer sheet and print the first letter of your first name in the FIRST NAME INI box. Mark (as described above) the corresponding circle below each of these letters.
3. Print your NetID in the NETWORK ID boxes, and then mark the corresponding circle below each of the letters or numerals. Note that there are different circles for the letter “I” and the numeral “1” and for the letter “O” and the numeral “0”. Do not mark the hyphen circle at the bottom of any of these columns.
4. This Exam Booklet is Version A. Mark the A circle in the TEST FORM box at the bottom of the front side of your answer sheet.
5. Stop now and double-check that you have bubbled-in all the information requested in 2 through 4 above and that your marks meet the criteria in 1 above. Check that you do not have more than one circle marked in any of the columns.
6. Do not write in or mark any of the circles in the STUDENT NUMBER or SECTION boxes.
7. On the SECTION line, print your DISCUSSION SECTION. (You need not fill in the COURSE or INSTRUCTOR lines.)
8. Sign (DO NOT PRINT) your name on the STUDENT SIGNATURE line.
Before starting work, check to make sure that your test booklet is complete. You should have 9 numbered pages including the Formula Sheet.
Academic Integrity—Giving assistance to or receiving assistance from another student or using unauthorized materials during a University Examination can be grounds for disciplinary action, up to and including expulsion.
Page 1 of 9
(21 problems)
Physics 101. / Hour Exam I / Summer 2015Exam Grading Policy—
The exam is worth a total of 117 points, and is composed of three types of questions.
MC5: multiple-choice-five-answer questions, each worth 6 points.
Partial credit will be granted as follows.
(a) If you mark only one answer and it is the correct answer,
you earn 6 points.
(b) If you mark two answers, one of which is the correct answer,
you earn 3 points.
(c) If you mark three answers, one of which is the correct answer,
you earn 2 points.
(d) If you mark no answers, or more than three, you earn 0 points.
MC3: multiple-choice-three-answer questions, each worth 3 points.
No partial credit.
(a) If you mark only one answer and it is the correct answer,
you earn 3 points.
(b) If you mark a wrong answer or no answers, you earn 0 points.
TF: true-false questions, each worth 2 points.
No partial credit.
(a) If you mark only one answer and it is the correct answer,
you earn 2 points.
(b) If you mark the wrong answer or neither answer, you earn 0 points.
You should assume that the acceleration of gravity near the surface of the earth is 9.8m/s2 downward, and ignore any effects due to air resistance.
The next five questions pertain to the following situation.
A cannon ball is fired from ground level, on a level surface, with a speed of vo = 30 m/s at an angle of q = 38° above the horizontal and returns to the same height.
1. At the top of its path, what is the speed of the cannon ball?
A. 0 m/s
B. 3.1 m/s
C. 9.8 m/s
D. 10.2 m/s
E. 23.6 m/s
2. At the top of its path, what is the direction of the acceleration of the ball?
A. up
B. down
C. left
D. right
E. the acceleration is zero
3. How long is the projectile in the air?
A. 1.2 s
B. 2.4 s
C. 3.8 s
D. 4.5 s
E. 6.0 s
4. How far does the projectile travel in the horizontal?
A. 43 m
B. 58 m
C. 72 m
D. 89 m
E. 106 m
5. What is the maximum height of the projectile above the ground?
A. 17 m
B. 21 m
C. 36 m
D. 42 m
E. 48 m
The next two questions pertain to the following situation
6. A batter swings and hits a ball. During the time that the ball is in contact with the bat the ball slows down, changes direction and speeds up in the other direction. As the ball slows down, compare the force that the bat applies to the ball, Fbat-ball, to the force that the ball applies to the bat, Fball-bat.
A. Fbat-ball < Fball-bat
B. Fbat-ball = Fball-bat
C. Fbat-ball > Fball-bat
7. As the ball speeds up after changing directions, compare the force that the bat applies to the ball, Fbat-ball, to the force that the ball applies to the bat, Fball-bat.
A. Fbat-ball < Fball-bat
B. Fbat-ball = Fball-bat
C. Fbat-ball > Fball-bat
The next two questions pertain to the following situation.
To the right is a graph of a car’s velocity vs. time.
8. What is the acceleration of the car at t = 12 sec?
A. -1 m/s2
B. -2 m/s2
C. -3 m/s2
D. -4 m/s2
E. -5 m/s2
9. How far did the car travel during the first 40 seconds?
A. 110 m
B. 137 m
C. 141 m
D. 250 m
E. 278 m
The next two questions pertain to the following situation.
10. A force of 5N is applied downward at
an angle of 300 with respect to the horizontal
on a block. There is friction between the
block and the floor and the block remains
stationary. What is the magnitude of the
normal force acting on the block?
A. FN = 10.5 N
B. FN = 15.1 N
C. FN = 19.8 N
D. FN = 22.1 N
E. FN = 24.6 N
11. The coefficient of static friction between the floor and block is μ = 0.5 What is the magnitude of the frictional force acting on the block?
A. Fμ = 4.3 N
B. Fμ = 8.7 N
C. Fμ = 10.6 N
D. Fμ = 12.0 N
E. Fμ = 13.4 N
The next two questions pertain to the following situation.
A block of mass m = 2 kg rests on another block of mass M = 5 kg on a frictionless floor as shown below. A constant force F is applied to the bottom block (mass M) and both blocks are observed to move together with constant acceleration a = 3.5 m/s2. (i.e. m does not slip relative to M)
12. What is the magnitude and direction of the force that block M applies to block m?
A. 7 N to the left
B. 12 N to the left
C. 18 N to the left
D. 7 N to the right
E. 18 N to the right
13. What is the magnitude of the force F?
A. 7.0 N
B. 12.6 N
C. 18.2 N
D. 20.3 N
E. 24.5 N
The next four questions pertain to the following situation.
Two blocks are being pulled along by a constant force T = 35N. Block A has a mass of 3kg and block B has a mass of 5kg. The floor is horizontal and frictionless.
14. What is T1, the tension in the rope between the two blocks?
A. 5.6 N
B. 8.1 N
C. 10.2 N
D. 13.1 N
E. 15.2 N
15. Now the blocks encounter a region where there is friction. The same 35N force is applied but now the blocks are moving with constant velocity. What is the net force on block A?
A. Fnet = 0 N
B. Fnet = 1.2 N
C. Fnet = 1.6 N
D. Fnet = 2.0 N
E. Fnet = 3.4 N
16. In the situation stated above in problem 15 where the blocks are now moving with constant velocity. Compare the tension T1 to your answer for T1 in problem 14.
A. T1 is greater now than it was in problem 15.
B. T1 is less now than it was in problem 15.
C. T1 is the same as it was in problem 15.
17. What is the coefficient of kinetic friction between the blocks and floor?
A. μ = .12
B. μ = .32
C. μ = .38
D. μ = .45
E. μ = .52
The next two questions pertain to the following situation.
A card, L = 0.13m long is held vertically by your friend between your fingers as shown in the photo below. When you see the card falling down you try to catch the card by closing your fingers without changing the vertical position of your hand.
18. How fast should your reaction time be to catch the card?
A. 0.12 s
B. 0.14 s
C. 0.16 s
D. 0.18 s
E. 0.20 s
19. Assuming your reaction time is not quite fast enough, what is the speed of the card when the top edge passes through your fingers (i.e., when the card has traveled 0.13 m)?
A. 0.8 m/s
B. 1.0 m/s
C. 1.2 m/s
D. 1.4 m/s
E. 1.6 m/s
20. A force T = 25N is applied to a block of mass 4kg at an angle of 300 above the horizontal. The surface between the floor and block is frictionless. If the block starts from rest, how long will it take to travel 4m?
A. 0.8 sec
B. 1.0 sec
C. 1.2 sec
D. 1.5 sec
E. 1.8 sec
21. An airplane needs to travel to a city 200km due north. There is a wind blowing due east at 25m/s. If the airplane maintains an airspeed of 55m/s, how long will it take to reach the city?
A. t = 58.2 min
B. t = 59.8 min
C. t = 61.6 min
D. t = 62.4 min
E. t = 68.0 min
Formula Sheet
Page 9 of 9
(21 problems)