Important: This test consists of 15 multiple choice problems, each worth points.

Transcription

1 Physics 214 Practice Exam 1 C Fill in on the OPSCAN sheet: 1) Name 2) Student identification number 3) Exam number as 01 4) Sign the OPSCAN sheet Important: This test consists of 15 multiple choice problems, each worth points. Instructions: For each problem, choose the one answer that is correct or most nearly correct. Make a small mark, for your eyes only, near the letter of your choice. After you finish and check all the multiplechoice problems, transfer your answers to the computer sheet. Then, until you hand in the computer sheet, turn the sheet over and leave it face down. Only answers on the computer answer sheet will be graded. As your OPSCAN answer sheet will not be returned, record the answers on the test paper that you will keep. The correct answers will be displayed on the course web page, and you can find your score for this exam on CHIP. This is a closed book exam, but a crib sheet is provided. You may also use a calculator. Any form of cheating will result in severe penalties, which will include a score of zero for this exam and may result in a grade of F for the course and referral to the Dean of Students. All electronic devices must be securely put out of sight and may not be touched during the exam. All cell phones and pagers must be turned off. The only items you are allowed are the exam, the opscan sheet, a pencil and a calculator

2 FORMULAE AND CONSTANTS Conversion Factors 1 inch = 2.54 cm 1 ft = 30.5 cm 1 m = ft 1 km = miles 1 mile = 5280 ft 1 nautical mile = miles 1 kg = lbs (where g = 9.8 m/s 2 ) Equations s = d/t s = d/δt v = d/δt (vector) a = Δv/Δt (vector) v = v 0 + at d = v 0 t + ½at 2 v 2 = v ad d = ½(v + v 0 )t F = ma (vector) W = mg Constants g = 9.8 m/s 2 π =

3 a = v 2 /R F = mv 2 /R F = GM 1 M 2 /R 2 W = Fd P = W/t KE = ½ mv 2 PE = mgh PE = ½ kx 2 P = mv FΔt = P f P i = Δp F external = 0, Δp = 0 centripetal acceleration centripetal force gravitational force work power Kinetic energy potential energy potential energy momentum impulse momentum conservation Circumference = 2πR g = 9.8 m/s 2 G = N m 2 /kg 2 π = ω = θ/t = Δθ/Δt α = Δω/t ω = ω 0 t + αt θ = ω 0 t + ½ αt 2 Torque = Fl = τ L = Iω τ = Iα τ external = 0,

4 1.An iron vise falls from rest at a great height. Neglecting air resistance, what distance has it fallen in the first 5 seconds? A. 122 m. B. 245 m. C. 49 m. D. 98 m. 2. Which of these graphs would be correct for the speed of a ball thrown upward? A. C B. D C. A D. B 3. An auto, starting from rest, undergoes constant acceleration and covers a distance of 1200 meters. The final speed of the auto is 60 meters/sec. How long does it take the car to cover the 1200 meters? A s. B. 40 s. C. 72,000 s. D. 20 s. 4. A certain rope will break if the tension in the rope reaches 100 pounds. Two persons, one on each end start to pull on the rope in opposite directions each pulling with a force F and gradually increasing F. At what value of F does the rope break? A. 50 pounds B. 25 pounds C. 100 pounds D. 200 pounds

5 5. A ball of mass 2kg is thrown with a horizontal velocity of 10m/s and a vertical velocity of 5m/s. What is the kinetic energy of the ball in joules at it s highest point? A. 200 B. 125 C. 225 D. 25 E A roller coaster of mass 800kg starts from rest 60m above ground. At a lower point 40m above ground it has kinetic energy of 100,000 joules. How much energy in joules has been lost due to friction? A. 84,500 B. 56,800 C. 370,400 D. 43,600 E. 213, If air resistance can be ignored, which of the following graphs will be a straight line for a falling object? A. Displacement versus velocity. B. Time versus displacement. C. Velocity versus displacement. D. Velocity versus time. E. Displacement versus time. 8. A box is moved 10 m across a smooth floor by a force making a downward angle with the floor, so that there is effectively a 10 N force acting parallel to the floor in the direction of motion and a 5 N force acting perpendicular to the floor. The work done is A. 50 J. B. 10 J. C. 100 J. D. 150 J. E. 5.0 J.

6 9. An elevator of mass 500 kg is caused to accelerate upward at 4.0 m/s 2 by a force in the cable. What is the force exerted by the cable? A. 2,900 N B. 2,000 N C. 4,900 N D. zero E. 6,900 N 10. A 10.0 kg block on a smooth horizontal surface is acted upon by two forces: a horizontal force of 70 N acting to the right and a horizontal force of 30 N to the left. The acceleration of the block will be: A. 4.0 m/s 2 to the right. B m/s 2 to the right. C m/s 2 to the right. D. 2.3 m/s 2 to the right. 11. A car rounds a curve while maintaining constant speed. The correct statement is: A. No net force acts on the car. B. The acceleration of the car is zero. C. The velocity of the car is zero. D. The velocity of the car is constant. E. A net force acts upon the car. 12. Refer to the graph. The speed of the object is largest A. in region B. B. in region A. C. in region E. D. in region C. E. in region D.

7 13. A Ferris wheel of radius 12m makes one revolution in 8 seconds. What is the apparent weight in Newtons of a 60kg person at the highest point? A. 2.4 B C D E The orbit of Earth about the Sun is not a circle; Earth is closer to the Sun in December than it is in June. Thus, the speed of Earth as it moves about the Sun is A. greater in December than in June. B. greater in June than it is in December. C. steadily increasing all year long. D. the same all year long. E. steadily decreasing all year long. 15. A motor outputs power of 900 watts which is used to raise an object which weighs 49N vertically at constant speed. How long in seconds does it take to raise the mass 15 meters? A B C D E. 3.25

8 Answer Key 1.A 2.C 3.B 4.C 5.E 6.B 7.D 8.C 9.E 10.A 11.E 12.E 13.D 14.A 15.C