Physics Fundamentals Study Guide

Transcription

1 Physics Fundamentals Study Guide Items to gather: 1. Any colorful helpful unit sheets 2. All Friday quizzes 3. All free responses from tests On the Day of the Final: May Items to bring: 1. Calculator (using the one in the classroom is fine) 2. #2 pencils 3. An eraser 4. Final helpful sheet On the day of the final: 1. MC choice Final 2. Turn in the final helpful sheet 3. Turn in the study guide (eligibility for the final curve) Semester 2 Topics: Energy Momentum Electrostatics & Electricity Waves (Sound & Light & Color) Reflection & Refraction Mirrors & Lenses

2 Energy Problems Key Ideas to remember about Energy

3 1. A greyhound at a race track can run at a speed of 16m/s. What is the KE of a 20kg greyhound as it crosses the finish line? 2. A child jumping rope is constantly converting energy from one form to another. If a child is a really good jumper they can maybe jump.2m off the ground. a) What type of energy does the child use to jump? b) If the child has a mass of 30kg what is their GPE at the top of their jump? c) ) As the child falls they loose GPE since energy is CONSERVED what does the GPE energy become? d) What is the velocity of the child right before they hit the ground? 3. Use the ski diagram above for the following calculations: a) What is the total energy of the system: b) Find the initial height of the snow boarder if his mass is 80 kg: c) Find how high the snowboarder is when she has a gravitational PE of 15,000J d) Find how fast she is moving when she has a KE of 35,000J: e) How Fast is the snowboarder when he is at ground level?

4 WORK, POWER, MACHINES 4. You use 200 N of force to push a snow shovel 10 m along the ground. How much work was done? 5. A painter lifts a 3 kg can of paint 3 m above the floor. How much work was done? 6. How much work is done if 500 W of power is used over 2 minutes? Use the diagram to the left for the next three questions. 7. How much work is done by pushing the 10 N box 12 meters? a. 12 J b. 15 J c. 110 J d. 120 J 8. How much force is required to lift the box up 4 m? a. 10 N b. 20 N c. 30 N d. 40 N e. 9. What is the mechanical advantage of this incline? a. 0.5 c. 3 b. 2 d. 5

5 Momentum Problems Key Ideas to remember about Momentum 10. If the moon had a mini moon that had a mass of, 1,000 kg and traveled at a velocity of 10 m/s, what is its momentum? 11. Two cows are moving with the same momentum. Is it possible for them to have different velocities and why.

6 Two carts are connected by a rubber band and are both released at the same time. When the two carts collide they stick together. Answer the following questions: Assume cart A has a much lower mass. A B 12. : ( A / B / Same) Which cart will be moving faster after they are released? 13. : ( A / B / Same) Which cart feels the greatest force from the rubber band? 14. : ( A / B / Same) Which cart feels the greatest impact force during the collision? 15. : ( A / B / Same) Which has the greatest momentum? 16. : After the carts collide what direction will they be moving? ( / / No Where) 17. : The type of collision that occurs is: (elastic or inelastic) 18. : After the carts collide, what will be the value of their momentum? a) zero b) greater than zero c) less than zero d) none of the above 19. A 1000kg cannon containing a cannon ball, is sitting stationary on ice (negligible friction) before firing. The cannon fires the ball and the cannon is observed recoiling with a speed of 3m/s to the left. What is the mass of the cannon ball if the cannon ball is moving with a speed of 300 m/s? (Assume momentum is conserved.)

7 Key Ideas to remember about Electricity 20. Current is measured using what unit? 21. In copper wire, what exactly is it that constitute the electric current? 22. If a 12 V battery is connected to a circuit with 2 A of current through a resistor, what is the value of the resistor? 23. When resistors are put in parallel, the overall resistance of the circuit is a. smaller than the resistance of any of the resistors b. the same as the resistance of one of the resistors c. larger than that of any of the resistors

8 24. When two light bulbs are connected in series, the d. current through each light bulb is proportional to the resistance of the bulb e. same amount of current always flows through each bulb f. half the current goes through each bulb 25. You observe a circuit where one of the light bulbs burns out but the other bulbs remain lit. You surmise that the type of circuit is a. series b.parallel c. perturbation d. short 26. The charge of an electron is A) positive. B) negative. C) Electrons have no charge. 27. A volt is a unit of A) charge. B) electric potential. C) electric potential energy. D) current. E) work. 28. A 2-C charge is located near a positively charged sphere so that it has 40 J of electric potential energy. Its electric potential is A) 80 V. B) 40 V. C) 20 V. D) 10 V. E) 2 V.

9 Key Ideas to remember about Waves & Sound Key Ideas to remember about Waves & Sound 29. The time needed for a wave to make one complete cycle is its. 30. The time that a pendulum takes to swing back and forth is called its. 31. If astronauts on the moon were to set off an explosive, would they hear it? Why or why not? 32. Which is faster- sound waves, light waves, or do they both travel at the same speed? 33. You saw a flash of lightening and then heard the thunder 2 seconds later. If the speed of sound is 340 m/s, how far away was the lightening?

10 34. If a sound wave travels at 340 m/s with a frequency of 170 Hz, what is the length of one of its waves? 35. You can hear beats when two tuning forks are sounded together. The tuning forks have labels showing them to be 242 Hz and 248 Hz frequencies. What is the frequency of the beats? 36. Jake wants to topple the trunk of a small tree he is cutting down. Jake finds that if he lets the trunk swing at its natural frequency and pushes as hard as he can every time the trunk sways away from him, the trunk will deflect more and more. Eventually the trunk swings so far over that it falls. What principle of physics is Jake wisely using? a. perturbation b. statics c. resonance d. photosynthesis 37. Sound is an example of a a. Doppler wave. b. transverse wave. c. constructive wave. d. longitudinal wave 38. Compared to the speed of light, sound travels a. slower b. faster. c. at about the same speed. 39. A 340-Hz sound wave travels at 340 m/s in air, with a wavelength of d. 0.1 m. e. 1 m. f. 10 m. g. 100 m. h. none of the above

11 Key Ideas to remember about Light, Color, & Pigments 40. Light acts as a a. particle b. wave c. both wave and particle d. neither wave nor particle 41. You are testing to see if sunglasses at the mall have polarizing lenses. When you overlay two lenses at right angles and look through them, what should you see if both the sunglasses have polarizing lenses? a. a pleasantly tinted lens b. total blackness c. completely clear lenses

12 42. List the three primary colors of light. 43. List the three primary colors of pigment. 44. What color results when red and blue are projected onto a white screen? 45. The complementary color of red is 46. A blue sheet of paper reflects light and absorbs light. What color would the paper appear if a. Only blue light were shining on it? b. Only red light were shining on it? 47. A radio wave has a wavelength of 300 m. What is its frequency? (c = 3x10 8 m/s) 48. If two Polaroid filters are held with their polarization axes at right angles to each other, the amount of light transmitted compared to when their axes are parallel is a. twice as much. b. zero. c. half as much. d. the same. 49. The three primary colors of light addition are a. red, green, and blue. b. red, yellow, and blue. c. red, yellow, and green. d. yellow, green, and blue. e. yellow, cyan, and red. 50. The complementary color of blue is a. violet. b. yellow. c. green. d. cyan. e. magenta.

13 Key Ideas to remember about Reflection and Refraction

14 A B C D Mirror 51. Which letter in the diagram above indicates an Incident Ray? a. none b. A c. B d. C e. D 52. Which number in the diagram above indicates the angle of reflection? a. 3 b. 2 c. 1 d. 4 e. none of the above 53. A lens for which parallel rays of light meet after passing through it is called a a. converging lens. b. diverging lens c. mirror d. there is no such thing 54. When light goes from a lower density material to a higher density material, its speed a. stays the same b. increases c. decreases