SAMPLE EXAM I: 1. 2. PHY 1114 Fall 2012 Professor K. Tapp Give the fundamental unit in the system specified. a) ___________________ SI unit of length b) ___________________ British unit of length c) ___________________ SI unit of time Give the agreed SI prefix for each power-of-10 multiple. a) ___________________ 106 b) ___________________ 10-2 c) ___________________ k 3. Convert 60 mph to km/s if 1 mile = 1.6 km 1 hour = 60 min 1 min = 60 s 4. Define a vector quantity and a scalar quantity and given an example of each. 5. Find the x and y components of this vector. = 4 N at a direction of 35° with respect to the x axis. 6. Find the magnitude and direction of a vector whose components are: Bx = +7 m By = +3 m 7. A runner travelling at a constant speed runs 105 m in 15 s. (a) What is the runner's average speed? (b) How far will the runner go in 20 s? 8. A Boeing 727 jet airliner accelerates uniformly from rest to 86 m/s in 40 s. (a) What is its average acceleration? (b) If the average were 1.85 m/s2, how fast would it be traveling after 40 s, starting from rest? 9. An automobile enters a freeway on-ramp with an initial speed of 40 ft/sec and accelerates at 3.0 ft/s2 for 10 seconds. (a) How far does the car travel? (b) What is the final speed of the automobile? 10. A stone is thrown vertically upward with an initial speed of 30 ft/s. Find (a) how high the stone rises, and (b) the time for the stone to return to the thrower. 1 11. If the Sun is a distance of 1.5 x 108 km from the Earth, how long, in minutes, does it take sunlight to reach the Earth if it moves at a constant speed of 3 x 108 m/s? 12. An airplane which has a 420 mi/hr ground speed in still air is flying with its nose toward the north. A 60 mi/hr wind is blowing 30° south of west. What are the magnitude and direction of the airplane's velocity relative to the ground? 13. A slingshot is used to project a pebble with an initial velocity of 40 m/s at an angle of 60° above the horizontal. Find (a) the maximum height, and (b) the range of the pebble. 14. At the instant a ball rolls off a rooftop it has a horizontal velocity component of +10.0 m/s and a vertical component (downward) of 15.0 m/s. Determine (a) the angle of the roof, and (b) what is the ball’s speed as it leaves the roof? 15. A baseball player hits a home run into the right field upper deck. The ball lands in a row that is 135 m horizontally from home plate and 25.0 m above the playing field. An avid fan measures its time of flight to be 4.10 s. Determine (a) the ball’s velocity components, and (b) the angle of its initial velocity. 16. A meteorologist tracks the movement of a thunderstorm with Doppler radar. At 8:00 pm, the storm was 60 mi northeast of his station. At 10:00 pm, the storm is at 75 mi north. Determine (a) the average velocity of the storm, and (b) the general direction of the thunderstorm’s velocity: (1) south of east (2) north of west (3) north of east (4) south of west 17. An object is observed to fall from a bridge, striking the water below 2.50 s later. (a) With what velocity did it strike the water? (b) How high is the bridge? Multiple Choice Questions: 1) The two measurements necessary for calculating average speed are a. acceleration and time. b. velocity and time. c. distance and time. d. distance and acceleration. e. displacement and time. 2) As an object freely falls, its a. velocity increases. c. both of the above. 3) b. acceleration increases. d. none of the above. The gain in speed each second for a freely falling object is about a. 0. b. 5 m/s. c. 10 m/s. d. 20 m/s. e. depends on the initial speed. 2 4) 5) 6) The meter is the standard unit of … a. time. b. length. One meter is equal to … a. 39.3701 inches. c. answers a & b. The metric system uses … a. meter, kilopounds, second c. meter, kilogram, second c. resistance. d. force. b. a little more than a yard d. none of the above. b. meter, pound, second d. inch, ounce, hour 7) 1000 meters equals _________ kilometers. a. 10 b. 1 c. 100 d. 2 8) Which force remains constant when an object falls? a. gravity b. air resistance. c. They both are constant. 9) A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is a. zero. b. less than 30 m/s, but larger than zero. c. about 30 m/s. d. more information needed for an estimate. 10) What is the acceleration of a car that maintains a constant velocity of 100 km/h for 10 s? a. 0 m/s2 b. 10 km/h/s c. 10 m/s2 d. 1000 km/h/s 11) A car accelerates from rest at 2 m/s2. What is its speed 3 s after the car starts moving? a. 2 m/s b. 3 m/s c. 4 m/s d. 6 m/s 12) Disregarding air resistance, objects fall at constant a. velocity. b. speed. c. acceleration. d. distances. 13) A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before striking the water a. is greater for the dopped bullet. b. is greater for the fired bullet. c. is the same for each bullet. d. depends on how high they started. 14) If you drop an object, it will accelerate downward at a rate of about 10 m/s2. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be a. less than 10 m/s2. b. 10 m/s2. c. greater than 10 m/s2. 15) Ten seconds after being dropped from the top of Seattle’s Space Needle, a freely falling penny will have a speed of about a. 10 m/s. b. 50 m/s. c. 100 m/s. d. 250 m/s. 3 16) An apple falls from a tree and hits the ground 5 m below. It hits the ground with a speed of about a. 5 m/s. b. 10 m/s. c. 15 m/s d. 20 m/s. 17) It takes 6 s for a stone to fall to the bottom of a mine shaft. How deep is the shaft? a. about 60 m b. about 120 m c. about 180 m d. more than 200 m 18) Consider drops of water that leak from a dripping faucet. As the drops fall, they a. get closer together. b. get farther apart. c. remain at a relatively fixed distance from one another. 19) Drop a rock from a 5-m height and it accelerates at 10 m/s/s and strikes the ground 1 s later. Drop the same rock from a height of 2.5 m and its acceleration of fall is a. about half. b. the same. c. more. 20) A wave travels an average distance of 6 m in 1 s. What is the wave's velocity? a. less than 0.2 m/s b. 1 m/s c. 3 m/s d. 6 m/s GOOD LUCK! 4