Questions for Final Exam with Answer Key - Foundations of Physics I | PHYS 2305, Study notes of Physics

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Physics 2305 - Final Practice Exam

Constants and conversions: g = 9.8 m/s^2 (gravitational acceleration near Earths surface) G = 6. 6710 −^11 N m^2 /kg^2 (gravitational constant) R = 3.21 J/(mol.K) (ideal gas constant) k = 1. 38 × 10 −^23 J/K (Boltzmann constant) 1 atm = 101 000 Pa (1 Pa = 1 N/m^2 ) 0 ◦C = 273.15 K

Specific heat capacity of liquid water = 4190 J/kg K Specific heat capacity of water ice = 2100 J/kg K Latent heat of fusion for water = 3. 34 × 105 J/kg Latent heat of vaporization for water = 2. 26 × 106 J/kg

Radius of Earth = 6. 38 × 106 m Mass of Earth = 5. 97 × 1024 kg

Mathematical Relations: c^2 = a^2 + b^2 − 2 abcosθ sin(90◦^ − θ) = cosθ cos(90◦^ − θ) = sinθ sin^2 θ + cos^2 θ = 1 sin 2 θ = 2sinθcosθ cos 2 θ = cos^2 θ − sin^2 θ

For small x: 1 + xn^ ≈ 1 + nx ex^ ≈ 1 + x sin x ≈ x cos x ≈ 1 − 12 x^2 tan x ≈ x If ax^2 + bx + c = 0, then x = −b±

√ b^2 − 4 ac 2 a

1. A machinist turns on the power to a grinding wheel, which is at rest at t = 0.0 s. The wheel accelerates uniformly for 8.0 s and reaches the operating angular velocity of 80 rad/s. The wheel is then run at that angular velocity for 30 seconds and then the power is shut off. The wheel decelerates uniformly at 5.0 rad/s^2 until the wheel stops. Through what total angle has the wheel turned?

(a) 2400 radians (b) 3360 radians (c) 4800 radians (d) 3520 radians (e) 4120 radians

2. A 450 kg space shuttle is traveling 6000 m/s in a circular orbit around Earth. How much work must be done by the ship’s rockets in order for it to completely escape the Earth’s gravitational pull?

(a) 28000 MJ (b) 8100 MJ (c) 16000 MJ (d) 3600 MJ (e) 700 MJ

3. A 2 cm radius marble (i.e. a solid sphere) starts from rest and rolls down a 2.0 m long ramp inclined at 30◦^ without slipping. The ball then rolls along the flat part of the table and rolls off the end of the 1.5 m tall table. Assuming that the marble experiences no air resistance, how far from the edge of the table (horizontally) will the marble hit the floor?

(a) 2.9 m (b) 1.7 m (c) 2.1 m (d) 0.74 m (e) 1.5 m

4. You round a curve of radius 50 m banked at 25◦^ on a warm summer day in Blacksburg. If the coefficient of static friction between your tires and the road is 0.28, for which range of speeds can you round the curve without slipping?

(a) 9.0 - 21 m/s (b) 10 - 18 m/s (c) 12 - 21 m/s (d) 13 - 26 m/s (e) 18 - 21 m/s

5. A 16 kg mass is suspended from the end of a rope around a 22 kg cylinder with a 6.0 m diameter. What torque applied to the drive axle of the cylinder is required to accelerate the 16 kg mass 2.0 m/s^2 upwards?

(a) 66 Nm (b) 1300 Nm (c) 630 Nm (d) 710 Nm (e) 1400 Nm

The following scenario will be the subject of the next two questions.

There is a ball attached by two pieces of string to a rotating rod as shown in the image above.

7. Which of the following forces does not belong on the free body diagram for the ball?

(a) mg (b) T 1 (c) T 2 (d) Frad

8. Which vector represents the net force on the ball?

(a) 1 (b) 2 (c) 3 (d) 4

9. Three boxes connected with string are attached to the roof of an elevator which is accelerating upwards. Rank the tensions in the strings from greatest to least.

(a) T 1 = T 2 = T 3 (b) T 1 > T 2 > T 3 (c) T 1 < T 2 < T 3 (d) T 1 > T 2 = T 3 (e) T 1 = T 2 > T 3

12. You’re sitting on the bus, and you drop your book and pencil on the floor. The bus starts to brake and you notice that the pencil starts to roll toward the front of the bus, but the book remains stationary with respect to the floor. When the bus is braking, the net force on the book is pointing in which direction?

(a) Toward the front of the bus (b) There is no net force on the book (c) Toward the back of the bus

13. A sign is suspended by two wires as shown in the figure below. Is the tension in the left wire larger than, equal to, or smaller than the gravitational force exerted on the sign by the Earth?

(a) Larger (b) Equal (c) Smaller (d) Not enough information is given

14. A small car is pushing a larger truck that has a dead battery. The mass of the truck is larger than the mass of the car. Which of the following statements is true?

(a) The car exerts a force on the truck, but the truck doesn’t exert a force on the car. (b) The car exerts a larger force on the truck than the truck exerts on the car. (c) The car exerts the same amount of force on the truck as the truck exerts on the car (d) The truck exerts a larger force on the car than the car exerts on the truck (e) The truck exerts a force on the car, but the car doesn’t exert a force on the truck

16. The figure below shows two different processes taking an ideal gas from state i to state f. Is the heat added during process A greater than, less than, or equal to the heat added during process B?

(a) Greater (b) Equal (c) Less

17. Sandra Bullock and George Clooney are playing a game of catch in deep space. Both are initially at rest. George throws a ball at Sandra and Sandra catches the ball over her head. After she catches the ball, which of the following statements are true?.

I. Sandra begins to rotate II. Sandra’s center of mass begins to translate III. The total kinetic energy of Sandra and the ball is the same as it was before Sandra catches the ball IV. The total momentum of Sandra and the ball is the same as it was before Sandra catches the ball

(a) I and II (b) I, II, III, and IV (c) II, III, IV (d) I and IV (e) I, II, and IV

18. Masses are placed on a moveable piston of a gas cylinder and the system is allowed to come to equilibrium. This state will be known as “state i”. The gas cylinder is then placed on a block of ice and then reaches a new equilibrium. This state will be known as “state f”. For the process that takes the gas cylinder from state i to state f, which quantities are zero throughout the process if your system is the gas?

(a) ∆T (b) W (c) ∆V (d) Q and ∆T (e) None of the above

21. Five stages of a satellite in elliptical orbit around a planet are shown in the figure above. Rank the speed of the satellite in each of the five stages from greatest to least.

(a) 1, 2 = 3, 5, 4 (b) 2 = 3, 1 = 4, 5 (c) 5 = 4 = 3 = 2 = 1 (d) 5, 3, 4, 1, 2 (e) 2, 1 = 4, 5, 3

22. Five stages of a satellite in elliptical orbit around a planet are shown in the figure above. Rank the total mechanical energy of the satellite-planet system in each of the five stages from greatest to least.

(a) 1, 2 = 3, 5, 4 (b) 2 = 3, 1 = 4, 5 (c) 5 = 4 = 3 = 2 = 1 (d) 5, 3, 4, 1, 2 (e) 2, 1 = 4, 5, 3

Answer Key

1. B
2. B
3. C
4. A
5. C
6. C
7. D
8. B
9. B
10. A
11. B
12. C
13. B
14. C
15. C
16. A
17. E
18. E
19. C
20. E
21. E
22. C