1. Physic s Final Exam Review -2015

2. Horizontal and Vertical Motion

3. Define Displacement – The straight line distance drawn from the object’s initial position to the object’s final position ΔX= X f -X i Velocity – The displacement divided by the time interval during which the displacement occurred. V = ΔX/Δt Acceleration – The rate of an object’s change in velocity. a = ΔV/Δt

4. If an object moves with a constant velocity, what is it’s acceleration? ZERO!!!! It does not speed up or slow down!

5. Which Runner is Faster???? Runner 1 is faster – the slope of the position vs. time graph is steeper! Runner 2 is slower – the slope of the position vs. time graph is less steep.

6. The ball is shown at each 1 second interval. Assuming only gravity acts on the ball, write in the velocity of the ball at each second. 39.2m/s 29.4m/s 19.6m/s 9.8m/s 0m/s -9.8m/s -19.6m/s -29.4m/s -39.2m/s -49m/s 49m/s

7. Atmosphere or Vacuum? Did these objects fall in an atmosphere or a vacuum? How do you know? Galileo's theory states that all objects will accelerate due to gravity at the same rate, regardless of mass, shape or size.

8. 1. How far does a car travel if, starting with a velocity of 2m/s, it drives for 5 seconds while accelerating at 4m/s 2 ? Δx = V i = Δt = a = ? 2m/s 5s 4m/s 2 Δx = V i Δt + ½aΔt 2 Δx = (2m/s)(5s) + ½(4m/s 2 )(5s) 2 Δx = (2m/s)(5s) + ½(4m/s 2 )(25s 2 ) Δx = (10m) + ½(100m) Δx = 10m + 50m Δx = 60m 2. Cristal bikes with a velocity of 12m/s and then accelerates at 3 m/s 2 for 20m. What is her final velocity? V i = 12m/s V f = ? Δx= 20m a = 3m/s 2 V f 2 = Vi 2 + 2a∆x V f 2 = (12m/s) 2 + 2(3m/s 2 )(20m) V f 2 = (144m 2/ s 2 ) + 2(3m/s 2 )(20m) V f 2 = 144m 2 /s 2 + 120m 2 /s 2 V f 2 = 264m 2 /s 2 V f = 16.2m/s

9. 3. Edelin started to drive her car with an initial velocity of 20m/s. If she drives for 6 seconds with an acceleration of 2m/s 2, what is her final velocity? V i = Δt = a = V f = V f = V i + aΔt 20m/s 6s 2m/s 2 ? V f = V i + a Δt 20m/s (2m/s 2 ) (6s) V f = 20m/s+ (2m/s 2 )(6s) 12m/s V f = 10m/s + 12m/s 32m/s V f = 32m/s 4. How fast is a penny going right before it hits the ground if it is dropped from a building 150m high? Δy = -150m V i = 0m/s a = -9.8m/s 2 V f = ? V f 2 = V i 2 + 2(a)(Δy) V f 2 = (0m/s) 2 + 2(-9.8m/s 2 )(-150m) V f 2 = 0 + (2940m 2 /s 2 ) V f 2 = 2940m 2 /s 2 V f = -54.2m/s V f = +54.2m/s

10. “Forces and the Laws of Motion”

11. 1.Define Force: 2.Define Net Force: 3.List 3 ways a Net Force can change motion: 4.Define Equilibrium: 5.Which force diagram shows an object in equilibrium? 6.An object in Equilibrium can have 2 motions: 7.What is the net force on a box moving with a constant velocity of 60m/s? 8.Draw a force diagram a) for a book at rest on a table. b) for a book falling and accelerating downward.

12. 1.Define Force: 2.Define Net Force: 3.List 3 ways a Net Force can change motion: Push or a Pull The sum of all the forces on an object. Speed Up Slow Down Change Direction

13. 4. Define Equilibrium: 5. Which force diagram shows an object in equilibrium? 6. An object in Equilibrium can have 2 types of motion: The forces on the object add to zero. F Net =0 The forces on the object are balanced. Motionless (not moving) Moving with a Constant Velocity (not speeding up, not slowing down, not changing direction) 7. What is the net force on a box moving with a constant velocity of 60m/s? constant velocity F Net = 0

14. 8. F N (Normal Force) (or F Table ) F air resistance F w (gravity) Different sized arrows show NET FORCE – accelerating! Same sized arrows show EQUILIBRIUM– at rest or constant velocity!

15. 1.What is Newton’s 1 st Law of Motion? Give examples. 2.What is Newton’s 2 nd Law of Motion?. Give examples 3.What is Newton’s 3 rd Law of Motion?Give examples. 4.What happens when a cart with a big mass and a cart with a small mass are pushed with the same force? 5.What happens if a person is moving in a car and then the car suddenly stops? 6.What happens when a balloon filled with air is released?

16. 1. What is Newton’s 1 st Law of Motion? “Inertia” “An object at rest will stay at rest and An object in constant velocity motion will stay in constant velocity motion Unless acted on by an unbalanced force.” Examples: Tablecloth trick, Hoop/Nuts,, Car Accidents (Seatbelts), Ball in Truck 2. What is Newton’s 2 nd Law of Motion ? List at least two examples of the 2 nd Law shown in class. “F=ma” “The acceleration of an object is directly proportional to the force applied to object and inversely proportional to the object’s mass” Examples: Skateboarders, Basketball and Tennis Ball, Heavy and Light Carts, Earth and Object

17. 3. What is Newton’s 3 rd Law of Motion? List at least two examples of the 3 rd Law shown in class. Action/Reaction “For every force applied to an object, the object applies an equal and opposite force back.” Examples: Balloon Rocket, Walking, “Pushing off table”, Newton’s Cradle, Punching A Face 4. What happens when a cart with a big mass and a cart with a small mass are pushed with the same force? The cart with more mass took more time to reach the end of the track, the cart with less mass got there faster! So … The more mass, the less acceleration! Newton’s 2 nd Law!

18. 5. What happens if a person is moving in a car and then the car suddenly stops? Newton’s 1 st Law!!! If the car suddenly stops the person will continue moving. There was a force on the car, so the car stops. But there is no force on the person, so they continued moving. 6. What happens when a balloon filled with air is released? Newton’s 3 rd Law!! When released, The balloon moved forward and the air moved backwards. The balloon pushed the air out (action), so the air pushed the balloon too (reaction)!

19. 1. What is the net force on a box which has a mass of 20kg and an acceleration of 5m/s 2. F = ma F = (20kg) x ( 5m/s 2 ) F = 100 kgm/s 2 F = 100 N F = ? m = 20kg a = 5m/s 2 2. What is the acceleration of a 200kg car pushed with a force of 600N? a = ? m = 200kg F = 600N F = ma 600 N = (200kg) x (a) 600 kgm/s 2 = (200 kg)(a) 200kg 200kg 3m/s 2 = a

20. “Circular Motion”

21. 1.What is the centripetal force? 2. What provides the centripetal force in each case below: A skateboard turning a corner. A person swinging on a swing set. The moon orbiting around the Earth A cart on a rollercoaster. 3. Below is a diagram of a record spinning – which of the points is moving with a greater tangential speed, the inside of outside? Answer the following questions: The force that pulls an object inward, and changes the direction of an object. It causes circular motion. Friction between the ground and tire. The rope Gravity The track The outside point has a greater tangential speed. It has to cover more distance (circumference) in the same amount of time because it is farther from the center (has a greater radius).

22. 1. A girl swings a bucket of water over her head so that it has a tangential speed of 6m/s. If the rope pulling the bucket is 0.75m long (radius), what is the bucket’s centripetal acceleration? a c = V t = r = ? 6m/s 0.75m a c = V t 2 r a c = __(6m/s) 2 0.75m a c = (36m 2 /s 2 ) 0.75m a c = 48m/s 2 2. What is the centripetal force of a 500kg rollercoaster car being pushed around a track with a radius of 100m if its tangential speed is 25m/s? F c = mV t 2 r F c = (500kg)(25m/s) 2 100m F c = (500kg)(625m 2 /s 2 ) 100m F c = (312500kgm 2 /s 2 ) 100m F c = 3125N m = 500kg V t = 25m/s F c = ? r = 100m

23. “ Energy and Energy Conservation”

24. 1. List the 5 types of Energy. 2. Write which type of Energy you listed above is present in each of the following examples: a)A bicycle coasting along a level road b)Heating water c)Microwave Oven used to heat food d)Glowing embers in a campfire (hot coals). e)A strong wind f)The Sun fusing hydrogen atoms into helium atom g)A swinging pendulum h)A rocket being launched into space. Chemical, Electromagnetic, Nuclear, Mechanical, Thermal Mechanical Thermal Electromagnetic Thermal Mechanical Nuclear Mechanical Chemical

25. Kinetic Energy Equation KE = ½mv 2 The Energy of Motion KE = ½(mass)x(velocity) 2 Potential Energy The Energy of Position Equation PE g = mgh PE g =(mass)x(gravity)x(height)

26. Point 1Point 2Point 3Point 4Point 5 PE g 900 J550 J KE300 J ME Label the types of energy (PE or KE) the rollercoaster has at each point. Then Fill out the table below using the Law of the Conservation of Mechanical Energy Note: At point 1 the velocity is 0m/s. Point 2 and 4 are at the lowest point. 0 J 900 J 0 J 900J 350J 900J 600J PE KE PE + KE KE

27. 1. Calculate the potential energy of the 10kg rock at the top of a 20m high cliff. PE = ? m = 10kg h = 20m PE = mgh PE = (10kg)(9.8m/s 2 )(20m) PE = 1960 J 2. Calculate the kinetic energy of the 10kg person moving at 5m/s at the bottom of a hill. KE = ? m = 10kg v = 5m/s KE = ½mv 2 KE = ½ (10kg)(5m/s) 2 KE = 125 J

28. “Impulse & Momentum” “The Conservation of Momentum”

29. What is momentum? What is the equation for momentum? What does the Impulse-Momentum Theorem state? What does the “Law of the Conservation of Momentum” state? The total momentum of a system will stay the same before and after a collision. p = mv The product of an object’s mass and velocity For a given change in momentum the more time applied to stop an object the less force needed to stop it.

30. Which object has more momentum? p = mv p = (0.009kg)(500m/s) p = 4.5kgm/s p = mv p = (2kg)(2.25m/s) p = 4.5kgm/s They have the same momentum!

31. What type of protection do each of these offer? Elastic bands in an egg-drop project. Bumpers that collapse of the front of a car. Helmets – for sports, biking, motorcycles etc… Highway guardrails. Spiderman’s web. Cell phone covers. Suspension Crumple Zone Cushion Crumple Zone Suspension Cushion

32. 1. A person kicks a ball with a force of 108N if the person and the ball are in contact for 0.030s, what is the impulse (change in momentum)? Δp = ? F = 108N Δt = 0.030s Δp = FΔt Δp = 108N(0.030s) Δp = 3.25kgm/s 2. A man’s 1.5kg hand hits a punching bag with a velocity of 3m/s and it stops the man’s hand, what is the impulse (change in momentum)? m = 1.5kg V i = 3m/s V f = 0m/s Δp = ? Δp = mv f - mv i Δp= (1.5kg)(0m/s) – (1.5kg)(3m/s) Δp= 0kgm/s – 4.5kgm/s Δp= – 4.5kgm/s

33. Perfectly Inelastic For each of the following examples, identify the type of collision… Elastic Perfectly Inelastic Inelastic Perfectly Inelastic Elastic

34. Using the diagrams below, determine the missing variable for each collision. 70kgm/s -450kgm/s 20kgm/s

35. Waves & Wave Properties Sound Waves & Light Waves

36. Label the following examples as transverse or longitudinal waves. transverse longitudinal

37. Sound and Light Waves Sound travels at approximately 340m/s in air. Light travels at 300,000,000m/s (3x10 8 m/s) in a vacuum. Why do you see lightening before you hear it? – Because light travels faster than sound. Why is it wrong to see and hear an explosion in outer-space? - Light can travel in a vacuum --- sound cannot travel in a vacuum. - So in outer space you can SEE things – but you can’t hear them!

38. Moving towards– higher frequency High frequency means high pitch! When does the person hear a higher pitch? When the car moves towards or away from him? When does the person see a redder wave? (red shift) When the light source is moving toward or away from him? lower frequency (redder waves) (moving away)

39. Electromagnetic Spectrum “Light Waves” Parts of the Electromagnetic Spectrum have different properties. These properties are based on their frequency and wavelength. f λ Low Energy f λ High Energy 1.What wave has the highest frequency? 2. Which wave has a higher wavelength than microwaves? 3. Which wave moves the fastest through a vacuum? Gamma rays Radio waves They all have the same speed – the SPEED OF LIGHT!

40. 1.A water wave has a frequency of about 300Hz and a wavelength of 2.5m, what is the speed of this wave? V = f λ V = 300Hz(2.5m) V = 750m/s V = ? f = 300 Hz λ = 2.5m 2. A guitar emits frequencies that range from a low of about 50Hz. Find the wavelength in air when the speed of sound is air is 340m/s. V = 340m/s f = 50 Hz λ = ? V = f λ 340m/s = 50Hz(λ) 6.8m = (λ) 50 Hz