physics Review

1. A unit used for a vector quantity is Watt Newton Kilogram Second 2. A displacement vector with a magnitude of 20. meters could have perpendicular components with magnitudes of 10. m and 10. m 8.0 m and 12. m 12 m and 16 m 8.0 m and 16 m 3. A hiker travels 1.0 kilometer south, turns and travels 3.0 kilometers west, and then turns and travels 3.0 kilometers north. What is the total distance traveled by the hiker? 3.2 km 3.6 km 5.0 km 7.0 km 4. A car with an initial velocity of 16.0 meters per second east slows uniformly to 6.0 meters per second east in 4.0 seconds. What is the acceleration of the car during this 4.0-second interval? 2.5 m west 2.5 m 4.0 m west 4.0 m 5. On the surface of planet X, a body with a mass of 10. kilograms weighs 40. newtons. The magnitude of the acceleration due to gravity on the surface of planet X is 4.0 × 103 m 4.0 × 102 m 9.8 m 9.8 m 6. A car traveling in a straight line at an initial speed of 8.0 meters per second accelerates uniformly to a speed of 14 meters per second over a distance of 44 meters. What is the magnitude of the acceleration of the car? 0.41 m 1.5 m 3.0 m 2.2 m 7. An object starts from rest and falls freely for 40. meters near the surface of planet P. If the time of fall is 4.0 seconds, what is the magnitude of the acceleration due to gravity on planet P? 0 m 1.3 m 5.0 m 10.0 m 8. If a block is in equilibrium, the magnitude of the block’s acceleration is zero increasing decreasing constant, but not zero 9. A car is moving with a constant speed of 20. meters per second. What total distance does the car travel in 2.0 minutes? 10. m 40. m 1200 m 2400 m 10. A car, initially traveling at 15 meters per second north, accelerates to 25 meters per second north in 4.0 seconds. The magnitude of the average acceleration is 2.5 m 6.3 m 10 m 20 m 11. An object is in equilibrium. Which force vector diagram could represent the force(s) acting on the object? 12. Which combination of fundamental units can be used to express the amount of work done on an object? kg•m kg•m kg•m2 kg•m2 13. An electric motor has a rating of 4.0 × 102 watts. How much time will it take for this motor to lift a 50.-kilogram mass a vertical distance of 8.0 meters? [Assume 100% efficiency.] 0.98s 9.8s 98s 980s 14. A compressed spring in a toy is used to launch a 5.00-gram ball. If the ball leaves the toy with an initial horizontal speed of 5.00 meters per second, the minimum amount of potential energy stored in the compressed spring was 0.0125 J 0.0250 J 0.0625 J 0.125 J 15. A ray of yellow light ( f = 5.09 × 1014 Hz) travels at a speed of 2.04 × 108 meters per second in ethyl alcohol water Lucite glycerol 16. What is the quark composition of a proton? uud udd csb uds 17. A student on an amusement park ride moves in a circular path with a radius of 3.5 meters once every 8.9 seconds. The student moves at an average speed of 0.39 m 1.2 m 2.5 m 4.3 m 18. Electrons in excited hydrogen atoms are in the n = 3 energy level. How many different photon frequencies could be emitted as the atoms return to the ground state? 1 2 3 4 19. Which graph represents the relationship between the magnitude of the gravitational force exerted by Earth on a spacecraft and the distance between the center of the spacecraft and center of Earth? [Assume constant mass for the spacecraft.] 20. When a 1.0-kilogram cart moving with a speed of 0.50 meter per second on a horizontal surface collides with a second 1.0-kilogram cart initially at rest, the carts lock together. What is the speed of the combined carts after the collision? [Neglect friction.] 1.0 m 0.50 m 0.25 m 0.0 m