PHYS 2305 Fall 2024 Practice Exam 1 New.pdf

Exam 1 Practice Problems Physics 2305 Fall 2024 Exam 1 will cover topics from Chapters 1–4.5 in our course text. The practice problems here reflect that material. Refer to the Schedule on our course Canvas page for specific...

Exam 1 Practice Problems Physics 2305 Fall 2024 Exam 1 will cover topics from Chapters 1–4.5 in our course text. The practice problems here reflect that material. Refer to the Schedule on our course Canvas page for specific sections covered. This practice set is not meant to provide a preview for the exact questions you will see on the exam. Instead, it is designed to give you additional practice problems to help you prepare for the exam. There are more questions in this practice set than will appear on the actual exam. The answer key can be found on the last page. 1 1. Object A has a position as a function of time given by sA (t) = (3.00 m/s) t ı̂+ (1.00 m/s2 ) t2 ȷ̂. Object B has a position as a function of time given by sB (t) = (4.00 m/s) t ı̂ + (−1.00 m/s2 ) t2 ȷ̂. What is the distance between object A and object B at time t = 3.00 s? (a) 18.2 m (b) 3.46 m (c) 15.0 m (d) 34.6 m (e) 29.8 m 2. If the fastest you can safely drive is 65 mi/h, what is the longest time you can stop for dinner if you must travel 541 mi in 9.6 h total? (a) 1.5 h (b) 1.2 h (c) 1.0 h (d) 0.5 h (e) You can’t stop at all 3. A cannon is fired from the top of a castle wall. The cannonball is fired at a speed of 45 m/s and an angle of 0.0◦ above horizontal. Another cannonball that was accidentally dropped hits the ground below in 1.2 s. How far from the castle wall does the fired cannonball hit the ground? (a) 47 m (b) 54 m (c) 7.1 m (d) 36 m 2 4. Approximately how fast must you toss a ball straight up in order for it to take 2 s to return to the level from which you tossed it? (a) 5 m/s (b) 7.5 m/s (c) 10 m/s (d) 15 m/s (e) 20 m/s Questions #5 & 6: The figure shows the path of a projectile from left to right. Points A–D represent the projectile at different locations along its trajectory. Consider the plot for the next two questions. 5. Which of the following choices lists the speed of the projectile at each point from greatest to least. (a) A, B, C, D (b) A, B = D, C (c) C, B = D, A (d) A = B = C = D 3 6. Which of the following choices lists the acceleration of the projectile at each point from greatest to least. (a) A, B, C, D (b) A, B = D, C (c) C, B = D, A (d) A = B = C = D 7. The magnitude of a vector can never be less than the magnitude of one of its components. (a) True (b) False 8. An object starts its motion with a constant velocity of 2 m/s towards the east. After 3.0 s, the objects stops for 1.0 s. The object then moves towards the west a distance of 2.0 m in 3.0 s. The object continues travel- ling in the same direction, but increases its speed by 1.0 m/s for the next 2.0 s. Which graph below could represent the motion of this object? 4  9. A light ball is dropped straight down off a ledge and hits the ground. A heavy ball is thrown straight down from the ledge, released at the same height as the light ball and hits the ground. Which quantities are different for the two balls? I. Time of flight II. Acceleration III. Velocity before impact (a) I (b) II (c) III (d) I and III (e) I, II, and III 10. Jan and Len throw identical rocks off a tall building at the same time. The ground near the building is flat. Jan throws her rock straight down- ward. Len throws his rock downward and outward such that the angle between the initial velocity of the rock and the horizon is 30◦. Len throws the rock with a speed twice that of Jan’s rock. If air resistance is negli- gible, which rock hits the ground first? (a) They hit at the same time (b) Len’s rock hits first (c) Jan’s rock hits first (d) It is impossible to know from the information given 5 11. This diagram represents a stroboscopic photograph (a superposition of multiple successive photographs) of an object moving along a horizontal surface in the direction shown by the arrow. The positions indicated in the diagram are separated by equal time intervals. The first photograph was taken just as the object started to move. Which of the following graphs (a)–(e) best represents the object’s velocity as a function of time? 12. A football is kicked at an angle of 55◦ to the horizontal at a velocity of 15 m/s. What is the maximum height reached by the football? (a) 3.8 m (b) 10. m (c) 7.7 m (d) 12 m 13. A hockey puck slides off the edge of a table with an initial velocity of 28.0 m/s and experiences no air resistance. The height of the tabletop above the ground is 2.00 m. What is the angle below the horizontal of the velocity of the puck just before it hits the ground? (a) 77.2◦ (b) 72.6◦ (c) 12.8◦ (d) 12.6◦ (e) 31.8◦ 6  Questions #14 & 15: The tallest cliffs ever discovered in our solar system are located on Uranus’s moon Miranda (g = 0.0772 m/s2 ). If you were to drop a rock off of one of these cliffs, it would take 12 min to hit the bottom. 14. How high is the cliff? (a) 20. km (b) 7.1 km (c) 250 km (d) 14 km 15. What is the speed of the rock when it hits the bottom? (a) 120 m/s (b) 70 × 102 m/s (c) 56 m/s (d) 60 × 101 m/s 16. The motions of a car and a truck along a straight road are represented by the velocity-time graphs in the figure below. The two vehicles are initially alongside each other at time t = 0. At time T , what is true about these two vehicles since time t = 0? (a) The truck will have traveled farther than the car. (b) The car will have traveled farther than the truck. (c) The truck and the car will have traveled the same distance. (d) The car will be traveling faster than the truck. 7 17. Batman drops his keys off a building that is 100. m tall and they fall straight down. He throws his grappling hook straight down 1.0 s after the keys fall to try to catch them. The initial velocity of the keys is 0.0 m/s and the initial velocity of the grappling hook is 10. m/s. How far about the ground does the grappling hook catch the keys? (Assume that the grappling hook is a simple projectile.) (a) Not before the keys hit the ground (b) 5.0 m above the ground (c) 35 m above the ground (d) 10. m above the ground (e) 25 m above the ground 18. A seaside cliff is 30 m above the ocean surface, and Sam is standing at the edge of the cliff. Sam has three identical stones. The first stone he throws off the cliff at 30◦ above the horizontal. The second stone he throws vertically downward into the ocean. The third stone he drops into the ocean. In terms of magnitude, which stone has the largest change in its velocity over a one second time interval after its release? (Sam’s throwing speed is 10 m/s.) (a) The first stone (b) The second stone (c) The third stone (d) Not enough information to determine (e) None of the choices above are correct 8 19. Some people in a hotel are dropping water balloons from their open win- dow onto the ground below. The balloons take 0.15 s to pass your 1.6 m- tall window. Where should security look for the raucous hotel guests? (a) 5.0 m above the top of your window (b) 10. m above the top of your window (c) 15 m above the top of your window (d) 20. m above the top of your window (e) 40. m above the top of your window 20. A player shoots a basketball from the free-throw line and the basketball lands in the basket. Now, suppose the player made the same shot from free-throw line on Mars where the acceleration of gravity has a magnitude of 3.8 m/s2. From the choices below, what could the player do to adjust her shot so that the basketball still goes in the goal? (a) Shoot the basketball at the same launch angle, but at a higher speed (b) Shoot the basketball at the same speed, but at a larger launch angle (c) Jump straight up and, while in the air, shoot the basketball at the same speed and same launch angle (d) None of the above 21. A battleship launches a shell horizontally at 100. m/s from the ship’s deck that’s 50. m above the water. The shell is intended to hit a target buoy in the water. However, when the shell is fired, a tailwind causes the shell to have a total acceleration of ⃗a = (2.0 m/s2 )ı̂ − (9.80 m/s2 )ȷ̂. As a result, the shell misses its target. How far away from the buoy will the shell land? (To clarify, if there were no tailwind, the shell would hit the buoy.) (a) 5.0 m (b) 10. m (c) 20. m (d) 30. m (e) 40. m 9 22. A motocross bike drives off of a jump angled at 45◦ above the horizon. When the bike leaves the jump, it has a speed of 20 m/s (about 40 mph). To ensure a smooth landing, the landing ramp needs to be at the same angle as the bike’s trajectory when it lands. If the landing ramp is 15 m lower than the jump, what angle below the horizon should the landing ramp slope down? (a) 30.◦ (b) 12◦ (c) 58◦ (d) 45◦ 23. Astronaut Mark Watney is very sick of potatoes. Therefore, he throws a potato at a 30.◦ angle above the horizontal as hard as he can. The initial height of the potato when it leaves his hand is 2.0 m, and its initial velocity is 5.0 m/s (about 10. mph). Gravitational acceleration on the surface of Mars has magnitude 3.8 m/s2. How far will Watney have to walk when he goes to retrieve the potato so he doesn’t starve? (Assume that the ground Watney is standing on is flat and level.) (a) 9.5 m (b) 5.6 m (c) 10. m (d) 8.1 m 24. While a car travels around a circular track at a constant speed, which are the following statements is correct? (a) The car’s acceleration is zero. (b) The car’s velocity is zero. (c) The car’s acceleration is constant and nonzero. (d) The car’s velocity is constant and nonzero. (e) None of the above statements are true. 10 25. Two particles, A and B, are in uniform circular motion about a common center. The acceleration of particle A is 8.5 times that of particle B. The period of particle B is 2.0 times the period of particle A. The ratio of the radius of the motion of particle A to that of particle B is closest to: (a) rA /rB = 2.1 (b) rA /rB = 4.3 (c) rA /rB = 18 (d) rA /rB = 0.24 (e) rA /rB = 17 26. The Earth’s radius is 6378.1 km. A mad scientist has come up with the simultaneously awesome and terrifying plan to increase the speed of the Earth’s rotation until people at the Earth’s equator experience a centripetal (radial) acceleration with a magnitude equal to g (9.80 m/s2 ), effectively making them experience weightlessness. If the mad scientist succeeds in their dastardly plan, what would be the new period of the Earth’s rotation? (a) 2.73 min (b) 84.5 min (c) 48.9 min (d) 76.8 min 27. An Amtrak high-speed train is traveling due east when it passes a cannon just as it is fired. The cannon is oriented along the direction of motion of the train and has a launch angle of 45.0◦. A passenger on the train notices that from her point of view the cannon ball seems to be traveling only in the vertical direction. She notices the cannon ball hits the ground 10.0 s after being fired. What can she determine about the train’s speed? (a) From her observations, the train is traveling about 251 km/h. (b) From her observations, the train must be traveling at about 176 km/h. (c) From her observations, the train is traveling about 129 km/h. (d) She does not have enough information to estimate the train’s speed. 11 28. One day you are driving your friends around town and you drive quickly around a corner without slowing down. You are going at a constant speed of 20.0 m/s (about 40.0 mph) to the north when you initiate the turn to the right. After 2.00 s, you finish the turn and are now traveling to the east, having always been moving at a constant speed of 20.0 m/s. What was the magnitude of the acceleration experienced by your unfortunate passengers, in terms of g (9.80 m/s2 ), during the turn? (a) 1.44g (b) 1.02g (c) 2.04g (d) 1.60g 12  Solutions 1. A 11. C 21. B 2. B 12. C 22. C 3. B 13. D 23. D 4. C 14. A 24. E 5. B 15. C 25. A 6. D 16. A 26. B 7. A 17. A 27. B 8. D 18. E 28. D 9. D 19. A 10. A 20. B 13