PHYSICS MIDTERM REVIEW PACKET PERIOD: TIME: DATE: ROOM: YOU NEED TO BRING: 1. #2 PENCIL W/ ERASER. 2. CALCULATOR (YOUR OWN). YOU WILL NOT BE ALLOWED TO SHARE OR BORROW!!! YOU WILL BE GIVEN: 1. FORMULA SHEET. 2. SCRAP PAPER FOR CALCULATIONS. THE TEST CONSISTS OF 90 MULTIPLE CHOICE QUESTIONS/PROBLEMS ON CHAPTERS 2-4, 6 4 OPEN-ENDED PROBLEMS CHAPTER QUESTIONS TOPICS 2 22 MOTION 3 21 VECTORS/PROJECTILES 4 27 FORCES 6 18 WORK AND ENERGY LABS 2 LABS
PART I. CONCEPTS. (just a sample) 1. Which will fall faster: a 10 kg ball or a 5.0 kg ball? 2. What two quantities are needed to determine the acceleration of an object? 3. Compare (ball thrown upward): The time it takes for a ball to go up and down. The velocity of the ball going up and the velocity of the ball when it returns. 4. What is the difference between a scalar and vector quantity? 5. Which has more inertia: a 5.0 kg block or a 15.0 kg block? 6. If you triple the net force on an object, its acceleration will increase by what factor? 7. A person is hanging on a rope. If the rope is pulled upward, what will happen to the tension? 8. If the net force on an object is zero, what can be concluded about its motion? 9. A person throws a ball horizontally; at the same instant an identical ball is dropped from the same height. Which one hits the ground first? 10. Two identical cars, one has 4x the KE of the other. Both cars lock their brakes. Which one will travel further before coming to rest? By how much? 11. What angle produces the maximum range? The maximum height? The longest time in air? 12. A horizontal force of 10.0 N is required to pull a cart at a constant speed. What is the friction force?
13. What quantity is zero when a projectile is at its maximum height? 14. What are the units for: distance, velocity, acceleration, force, work, energy, power 15. An object has a weight of 50 N on the Earth and a second object has a weight of 50 N on the moon. Which has the greater mass? 16. A car is being pulled by a force, suddenly the mass of the car doubles, what will happen to the cars acceleration? 17. A table cloth can be pulled from under a glass without it moving. This happens because of? PART II. PROBLEMS. (just a sample) 1. A car is traveling at 12.0 m/s. It skids to a stop in 4.50 m. What is the car s acceleration? 2. How much time is needed for a car to accelerate to 25 m/s if it starts from rest and accelerates at 3.5 m/s 2? [-16 m/s 2 ] 3. An arrow is shot upward at a speed of 6.50 m/s. A. How high will the arrow go? [2.15 m] B. How long will it be in the air? [1.33 s] C. What will be its speed when it returns to the same height? [-6.50 m/s] D. What is the acceleration of the arrow when it is at its highest? [-9.8 m/s 2 ] [7.1 s]
4. A 1500. kg plane lands and skids to a stop in 805 m on a surface whose μ K is 0.850. A. What is the frictional force on the plane? [12500 N] B. What is the plane s acceleration? [-8.33 m/s 2 ] C. What was the plane s initial velocity? [116 m/s] 5. A ball is thrown horizontally from atop a roof that is 6.00 m high at a speed of 2.25 m/s. A. How long will it take to hit the ground? [1.11 s] B. How far from the base of the building will it land? [2.50 m] C. What will be its velocity when it hits the ground? [11.1 m/s] 6. A cannonball is launched horizontally from a tower with a speed of 100 m/s. A. How far downrange will the cannon ball be after 2.0 seconds? [200 m] B. If it lands 350 m from the base of the tower, how tall is the tower? [60 m] 7. A rope whose tension is 65.0 N is pulling a 35.0 kg wagon. A. What will be the acceleration of the wagon if the surface is frictionless? [1.85m/s 2 ] B. What will be the acceleration of the wagon if μ K = 0.15? [0.39 m/s 2 ]
8. A force of 20 N is needed to pull a 8.0 kg block at constant speed. A. What is the friction force on the object? [-20 N] B. What is the coefficient of friction? [0.26] 9. A helicopter is flying horizontally with a speed of 45.0 m/s at an altitude of 65.0 m. The pilot is trying to save a castaway on an island and drops a care package. How far from the island should the pilot drop in order for the package to land on the island? 10. An 85.0 kg student is standing on a scale (Newton) in an elevator. What will the scale read if: A. The elevator is at rest? [833 N] B. The elevator accelerates upward at 3.0 m/s 2? [1088 N] C. The elevator accelerates downward at 7.50 m/s 2? [196 N] [164 m] 11. A 15.0 kg sled has an initial speed of 3.25 m/s at the top of a hill that is 12.0 m high. What will be its velocity when it reaches the bottom? 12. If it takes 50 J to push a crate 6.0 m across a floor, what force was applied to the crate? [15.7 m/s] [8.3 N]
13. A 15 N object is traveling at 3.0 m/s. What is its kinetic energy? [6.9 J] 14. How much power is required to lift a 45 N rock 5 meters in 2 seconds? 15. A car has 3000 J of kinetic energy. If its velocity is tripled its kinetic energy will be: [113 W] [27,000 J] PART III. SAMPLE FREE RESPONSE PROBLEMS 1. A train starting from rest, accelerates at a rate of 1.5 m/s 2 for 30 seconds. After this, the train continues at a constant velocity for 5 minutes more. The train then decelerates at a rate of 2.3 m/s 2 until it is stopped. What distance did the train travel from start to stop? [14,600 m]
2. A 500 g ball is rolling horizontally across a table at 5.0 m/s. How far from the edge will it land if the table is 2.3 m high? v 0 = 5 m/s 2.3 m 3. Add the following forces to determine the magnitude and direction of the resultant: [3.42 m] 4. Complete the following: [Mag: 202 N] [Dir: 21º N of E] 2 kg µ S = 0.30 µ K = 0.25 1.5 kg A. Show (quantitatively) that the blocks will move. B. What will be the acceleration of the blocks? C. What is the tension in the string while the blocks are moving? B. 2.80 m/s 2 C. 10. 5 N
5. Observe: m = 15 kg 4 m/s 35 m 25 m µ = 0.25 A. How fast is the block moving at B and C? B. If the block had only friction to bring the block to rest after the ride, how far would it travel before stopping? C. If instead of friction, the block had a spring to stop it after the ride whose spring constant is 850 N/m, how much distance would it compress? A. v B : 26.5 m/s v C : 14.6 m/s B. d = 143 m 6. Physics Graphs. C. 0.91 m x t A. Sketch the equivalent x-t graph. B. Calculate the acceleration from 0 to 3 seconds. [+3.3 m/s 2 ] C. What is the total distance traveled? [105 m] Displacement? [75 m]
Sketch the v-t graphs for (a) & (b). Sketch the x-t graphs for (d), (e), & (f) Calculate the total work done, and the spring constant from x= 4 to x = 6 meters. W = 25 J k = 2.5 N/m (k is always positive)