Unit 8: Thrills & Chills

Essential Questions How are the concepts of velocity and acceleration used when designing a rollercoaster? How does an incline angle affect the speed at which an object can reach? What is spring potential energy? What is the difference between mass and weight? How does your weight change on a rollercoaster? What are some necessary safety features on a rollercoaster? How is conservation of energy shown in rollercoasters? How are safety and thrills maximized when designing a rollercoaster?

Chapter Challenge You will work with a group (maximum 3 people) to design a rollercoaster Decide who your audience is (children, thrill-seekers, squeamish adults, etc.) Must include: 2 hills, 1 horizontal curve Create a model and a poster of your rollercoaster Due date: May 10

Day 1: The Big Thrill Learning Objectives: Draw and interpret a top view and a side view of a roller coaster ride Conclude that thrills in roller coaster rides come from accelerations and changes in accelerations Define acceleration as a change in velocity with respect to time and recognize the units of acceleration Be able to measure and calculate velocity and acceleration

Starter

Starter (cont’d) How high was the tallest roller coaster? Why can steel roller coasters be taller than wooden ones? Which part of the roller coaster produces the loudest screams? Why? Time: 15 minutes

Activity 1 In your lab groups, work through part A (#1, 2, 5) and B (#1-5) of “For you to do” (pg. 209) Compare your drawings to other groups in part A Show me your drawings when you finish Time: 30 minutes

Homework Read part C & D of “For you to do” Read Physics Talk, pg. 214 Physics to Go, pg. 216 #1, 4, 5

Day 2: What Goes Up and What Comes Down Learning Objectives: Measure the speed of an object at the bottom of a ramp Recognize that the speed at the bottom of a ramp is dependent on the initial height of release of the object and independent of the angle of incline of the ramp Complete a graph of speed vs. height of the ramp Define and calculate kinetic and potential energy State the conversion of energy Relate the conservation of energy to a roller coaster ride

Starter The steepest angle of descent on a wooden roller coaster is 70° The steepest angle of descent on a steel roller coaster is 90° Which roller coaster will give the biggest thrill between the two? Why? Time: 15 minutes

Video

Activity 1 Activity B from last lesson Time: 20 minutes

Activity 2 We will investigate how the angle and height of release of a marble on a track affects the speed of the marble For you to do, pg. 219 #1 – 5, 8, 9 Research how how a curved track would affect the speed an object can obtain Does height matter? Does the angle matter? Time: 45 minutes Due: Monday, April 22

Homework For you to read, pg. 223 Physics to go, pg. 237 #1, 2, 3, 5, 9

Day 3: More Energy Learning Objectives: Measure the kinetic energy of a pop-up toy Calculate the spring potential energy from the conservation of energy and using an equation Recognize the general nature of the conservation of energy with heat, sound, chemical, and other forms of energy

Starter The concept of a “lift hill” for a roller coaster was developed in This was the initial hill that began a roller coaster ride. A chain or a cable often pulled up the train to the top of this hill. How does the roller coaster today get up to its highest point? Does it cost more to lift the roller coaster if it is full of people? Time: 15 minutes

Video

Activity 1 What is kinetic energy? What is gravitational potential energy? Draw a side view of a roller coaster, and label on the diagram where the kinetic and potential energy would be the highest and lowest Time: 10 minutes

Activity 2 Read through “What is energy” and create a spider diagram that shows the differences between the different types of energy Time: 15 minutes

Activity 3 Complete the “energy in a golf ball” data sheet with your group After doing the 5 trials, calculate the speed at which the baseball hit the ground How will you calculate this? KE = PE (1/2mv 2 KE = PE (1/2mv 2 = mgh) Time: 35 minutes

Closing & Homework How do you calculate the speed of an object hitting the ground if you know its PE? For you to read, pg. 234 Reflecting on the Activity and the Challenge, pg. 237 Physics to go, pg. 237 #1, 2, 4, 6, 7

Day 4: Your “at rest” Weight (60 min) Learning Objectives: Distinguish between mass and weight Calculate weight in newtons Measure the effect of weight on the stretch of a spring Graph the relationship between weight and stretch of a spring Use a spring to create a scale and explain how Newton’s Second Law is used in the creation of the scale Calculate spring forces using Hooke’s Law

Starter A canary and an elephant have enormous differences in weight. The elephant may weigh more than 10,000 times as much as the canary Can you use the same scale to weigh a canary and an elephant? How does a bathroom scale work? Time: 10 min

Video

Activity 1: Mass and Weight If you were to drop a baseball and a bowling ball off the top of a building, which would land first? Test your answer by dropping two different materials with different masses Explain why you observed what you did (hint: think about acceleration due to gravity) Now, drop a baseball and a piece of paper. Which hits the ground first? Why? Time: 15 minutes

Activity 1 (cont’d) Modify the statement “all objects fall at the same acceleration” to account for your observation with the paper. What is the difference between mass and weight? What are the units of measure for each? Time: 15 min

Activity 2: The Properties of Springs Work through Part B of “For you to do” with your lab group Time: 30 min MassWeightStretch of SpringWeight /Stretch Data table for #6

Homework For you to read, pg. 246 Physics to go, pg. 251 any 3 calculation problems + #10

Day 5: Weight on a Roller Coaster Learning Objectives: Recognize that the weight of an object remains the same when the object is at rest or moving at a constant speed Explore the change in apparent weight as an object accelerates up or down Analyze the forces on a mass at rest, moving with constant velocity, or accelerating by drawing the appropriate force vector diagrams Mathematically predict the change in apparent weight as a mass accelerates up or down

Starter As the roller coaster moves down that first hill, up the second hill, and then over the top, you feel as if your weight is changing. In roller coaster terms, this is called airtime. It is the feeling of floating when your body rises up out of the seat. Does your weight change when you are riding on a roller coaster? If you were sitting on a bathroom scale, would the scale give us different readings at different places on the roller coaster? Time: 15 minutes

Video: Mass vs. Weight

Activity 1 Will a spring scale have the same reading with a mass suspended from it when you are moving at a constant speed? Why do you think this? Record your answer. Test your hypothesis by suspending a mass to the spring scale. Move your arm at a constant speed to see what happens to the reading on the scale. Explain what you see in terms of Newton’s First and Second Laws of Motion Draw a force diagram to show the forces that are acting on the mass Time: 15 minutes

Activity 2 What do you think will happen to the reading on the spring scale when you accelerate the spring scale up and down? Test your hypothesis and record your observations. You may find a diagram useful. Complete the observation table #7 on pg. 258 Time: 20 minutes

Activity 3: Video

Activity 3 Create a comic strip that depicts the difference between mass and weight and how they change (if they change) on a roller coaster Time: 30 minutes

Homework For you to read, pg. 259 Physics Talk, pg. 260 Physics to go, pg. 263 #1, 3, 4, 7

Day 6: On the Curves Learning Objectives: Recognize that an object in motion remains in motion unless acted upon by a force – Newton’s 1 st Law Explain how a force toward a fixed center will allow a car to travel in circular motion Describe how the centripetal force is dependent on the speed and the radius of the curve and the mass of the object Solve problems using the equation for centripetal force Recognize that safety considerations limit the acceleration of a roller coaster to below 4g

Starter The first looping coaster was built in Paris and had a 4m wide loop. One of the largest loops today is about 35m wide. Watch the video of the roller coaster that goes upside down Why don’t people fall out of the roller coaster when it goes upside down? Time: 15 minutes

Activity 1, 2, 3 For you to do, pg. 267 in lab groups Part A – we don’t have battery operated cars, but use 2 people (holding hands) Write down observations and force diagrams Part B – Write down observations and answer questions Part C – Write down observations and answer questions Time: 60 minutes (20 minutes for each part) Hand in on Thursday if not complete

Activity 4 You may use this time to discuss your roller coaster plans with your group Time: 15 minutes

Homework For you to do activities Physics talk, pg. 275 For you to read, pg. 277 Physics to go, pg. 282 #3, 4, 5, 6, 7, 8

Day 7: Getting Work Done Learning Objectives: Measure and recognize that the product of force and distance is identical for lifting the object to the same height irrespective of the angel of the ramp Define work as W = F  d Explain the relationship between work and GPE and SPE Define power as the rate of doing work and the units of power as watts

Starter The greatest drop for a roller coaster is 125m. It must be pulled up to that height to get the ride started. Does it take more energy to slide the roller coaster up a steep incline than a gentle incline? Why is it more difficult to walk up a steep incline than a gentle incline? Think about how to calculate energy, work, force, etc. Time: 10 minutes

Activity 1 You will investigate the amount of force required to lift a roller coaster car to a certain height You will use a ramp, cart, spring scale and meter stick In your lab group, write down your aim/objective, materials and procedure (this can be done as you go) I will give you a data table to complete Time: 40 minutes

Activity 2 Time to work on project

Homework Lab plan + data table & analysis For you to read, pg. 290 Physics to go, pg. 294 #1, 2, 3, 7

Day 8: Safety is Required but Thrills are Desired Learning Objectives: Calculate the speed of the roller coaster at different positions using conservation of energy Calculate the acceleration of the roller coaster at turns Determine if the acceleration is below 4g for safety Create sounds and scenery to enhance the thrills of a roller coaster ride

Starter In 2003, a person died on a roller coaster in Disneyland. They closed the roller coaster immediately. Accidents occur very rarely on roller coasters. Does the knowledge that people can get hurt or die on a roller coaster change the thrill of the ride? Would your answer change if you found out that ½ of all roller coaster rides ended in death of its passengers? Think of horror movies, movies about war, and being on an airplane in turbulence as you answer these questions Time: 15 minutes

Starter: Video

Activity 1 Safety is one of the criteria for your roller coaster design Brainstorm 3 reasons why safety is a major concern For the following “injuries”, how many people could get injured before you the ride should be closed? Give a number and a time period: Nausea Broken bones UnconsciousnessDeath Time: 15 minutes

Activity 2 The acceleration due to gravity on a roller coaster can not be more than 4g (4x F g ), as a person will become unconscious Where on a roller coaster is there acceleration? If a roller coaster were to fall straight down, what would be the acceleration? Is this a safety concern? Time: 5 minutes

Activity 3 A roller coaster is traveling at 30m/s at the bottom of the loop. The radius is 9.0m Using the conservation of energy, calculate the height of the roller coaster (KE = PE) Calculate the acceleration (a = v 2 /R). Is this a safety concern? At what speed would there be a safety concern? (v = (√aR) These are things to consider when assigning dimensions to your roller coaster For your roller coaster, calculate some speeds and accelerations to fit the safety requirements Time: 20 minutes

Activity 4 Another safety concern is the track must be strong enough to hold the roller coaster car without breaking. You can calculate the minimum strength of the car by assuming the car is filled with big football players or sumo wrestlers. What force would a roller coaster track have to supply to hold up a car filled with passengers if the total mass were 1000kg? (w = mg) Time: 5 minutes

Activity 5 With your group, answer question 5-11 Give yourself 1-2 minutes to answer each question. We will take up each answer as we go to make sure you’re on the right track Time: 20 minutes

Homework Chapter challenge: Due Friday Must include a model and a poster

Day 9 You may use this lesson to work on your chapter challenge which is due on Friday

Day 10 Presentation of roller coasters Take home test – you may begin so you don’t have as much to do at home Due: May 14