Unit D Energy-Analysis Questions Activity 53-Home Energy Use 1. How do Climates of the two home locations influence the energy used in the homes? 2. In the context of this activity, what does the term energy efficient mean? Explain, and give an example from this activity. 3. If the people who live in homes A and B have similar lifestyles, which home do you think uses less energy in a year? Use data from the table to support your choice. 4. What could be done to reduce the energy needs of: a. home A? b. home B? 5. Reflection: What steps have you and your family taken to reduce energy use in your home? Activity 54- Drive a Nail 1. Which combination of tube height and rod mass transferred the most and least energy to the nail? Explain the evidence you gathered to make this conclusion. 2. Where was the rod located when there was the most: a. gravitational potential energy? b. kinetic energy? 3. Do you think that all the energy from the rod transferred to the nail? Describe any evidence that showed it did or did not. 4. How do the following variables affect how much energy is transferred to the nail? a. mass od rod b. height of the rod c. shape of the rod 5. In the situation shown below, how much gravitational potential and kinetic energy does the block have at each position? a. When released from rest: Potential energy = 100 J Kinetic energy = b. Halfway down: Potential energy= Kinetic energy= c. Just before it hits: Potential energy = 0 Kinetic energy =
Activity 55- Roller Coaster Energy 1. Look at the diagram of a roller coaster below. At which point does a train on this roller coaster: a. have the most gravitational potential energy? Explain your choice. b. have the most kinetic energy? Explain your choice. c. have both kinetic and gravitational potential energy? Explain your choice. 2. Kinetic energy is related to the speed of an object. In which place, Point E or Point F, is the train moving faster? Explain in terms of kinetic energy. 3. As the train travels on the track, the energy of the train changes back and forth from the gravitational potential to kinetic. What other energy transformations occur as the train travels the track? Explain. 4. Why can t a roller coaster go up a hill that is higher than the hill it just came down? Activity 56- Shake the Shot 1. For each time interval, why did you perform three trials and then average the temperatures? 2. Describe any possible sources of error in your experiment, and explain how each may have affected your results. 3. Use evidence gathered in this investigation to describe the relationship between: a. shaking time and temperature change. b. shaking time and energy transfer.
4. Of the two descriptions below which, a or b, correctly describes the transformation of energy shown in the diagrams below? Explain your choice. a. Potential energy temperature b. Kinetic energy thermal energy Activity 57- The Conservation of Energy 1. Which of the following diagrams accurately applies the Law of Conservation of Energy to a toaster in use? Explain your choice. thermal energy a) Electrical energy light Sound b) Chemical potential energy thermal energy Light 2. Your friend tells you that a generator makes electricity. Do you agree or disagree with her statement? Explain why in terms of the Law of Conservation of Energy. 3. Your friend says that when he measured how much electricity was provided by a battery, it was less than the potential energy in the battery. He concluded that the transformation violated the Law of Conservation of Energy. Do you agree? Explain, using the ideas of the Conservation of Energy. 4. Which energy is often called the graveyard of kinetic energy and why? 5. What is the efficiency of an engine that gives off 70% thermal energy?
Activity 58- Following the Energy 1. Copy the lists of words shown below: List 1: List 2: List 3: kinetic energy chemical energy fossil fuels potential energy potential energy stored energy light nuclear energy chemical energy sound thermal energy absorb energy release energy a. Look for a relationship among the words in each list. Cross out the word in each list that does not belong with the others. b. Circle the word in each list that is a category that includes the others. c. Explain how the word you circled related to the other words in the list, and how the word you crossed out dies not fit in the list. 2. The diagram below shows the transfer of energy from the Sun all the way to a student using a computer. Using the table A Summary of Energy Types on the next page, decide on the type of energy at each of the situations. There may be more than one energy type at each place.
Unit E1 Force & Motion Activity 73- Choosing a Safe Vehicle 1. Compare the features you listed in Step 2 to the features listed on Student Sheet 73.1. How are they: a. similar? b. different? 2. For each feature on Student Sheet 73.1 that you drew and X next to, explain why you decided it was less important. 3. What factors other than safety do people consider when buying a car? 4. Do you think car features can: a. reduce damage, injuries, and fatalities in car accidents? Explain. b. prevent accidents? Explain.
5. Which vehicle do you think is safer Vehicle 1 or Vehicle 2? Explain what data convinces you that this vehicle is safer than the other one. Activity 74- Measuring Speed 1. According to your data from Part A, what is the speed of the cart? 2. According to your data from Part B, what is the effect of release height on speed? 3. List some common units for speed. Why are there so many different units? 4. What part(s) of your experimental design in Part B: a. increased your confidence in the results? b. decreased your confidence in the results? 5. What is a car s speed in m/s if it travels: a. 5 meters in 0.1 seconds? b. 5 meters in 0.2 seconds? c. 10 meters in 0.2 seconds? 6. Reflection: Why do you think speeding is a factor in about 20% of fatal car accidents? Activity 75 Interpreting Motion Graphs 1. Identify a place on each graph where the slope of the line changes. What does a change in the slope of a motion graph indicate? 2. Which student Teasha or Josh started out faster? Explain how you know this. 3. How far in into the trip did Josh turn around? Describe what the graph looks like at this point in the trip.
4. Look at the motion graphs shown below. Match the descriptions here to the correct graphs: a. a car moving at a speed stops and then moves in the opposite direction at the same speed. b. a car moving at a constant speed stops and then moves faster in the same direction. c. a car moving at a constant speed changes to a higher constant speed. d. a car moving at a constant speed changes to a lower constant speed. 5. A car that accelerates is one that changes speed and/or direction. Which graph below shows a car continually accelerating? Explain how the shape of the graph shows this. Activity 76- Speed and Collisions 1. How does the speed of the cart affect how far the block moves? 2. Why do you think release height has this affect?
3. What part(s) of the experiment s design: a. increase your confidence in the data? b. decrease your confidence in the data? 4. When a car crashes, do you think its speed can make a difference in the amount of damage done? Explain, using evidence from this investigation. Activity 77- Mass and Collision 1. Did the mass of the cart affect the collision? Explain how you know this. 2. Why do you think mass did or did not have the effect you predicted? 3. What part(s) of the experimental design: a. increase your confidence in the data? b. decrease your confidence in the data? 4. If your car were in a collision, would you rather be hit by Vehicle 1 (2,027 kg) or Vehicle 2 (1,415 kg) from activity 73? Explain. Activity 78- force, Acceleration, and Mass 1. Look at your graphed line for experiment 1. Explain why it does or does not indicate that there is a relationship between force and acceleration. 2. Compare the two lines, experiment 1 and experiment 2 on your graph. Identify and explain: a. any similarities. b. and differences. 3. In your science notebook, make a table like the one below. Use your equation for force, mass, and acceleration to find the missing values. 4. In the first activity, Vehicle 2 has a greater acceleration than Vehicle 1, but has a less forceful engine. How can this be? Explain in terms of your equation. 5. One newton of force is the same as 1 kg 31 m/s/s. Explain how this unit of measurement is appropriate for your equation.
Activity 79- Inertia Around a Curve 1. Describe the changes in direction and speed of the marbles when they traveled: a. inside the circular track. b. outside the circular track. 2. Describe any changes in the path of the marble that occurred when you changed: a. the opening position of the circular track. b. the mass of the marble. 3. Imagine that a car is approaching a curve in the road when it suddenly loses its steering and brakes. The area is flat and there is no guardrail on the road. a. Copy the diagram below in your science notebook. Then draw a line showing the car s path when it loses its steering and brakes. b. Explain why the car will take the path. c. How would your answer change if the car had more mass? Explain. Activity 80- Newton s Laws of Motion 1. Spaceships that travel millions of miles into outer space use very little fuel. How can they go so far on so little fuel? 2. Use Newton s laws to explain why it is easier to turn a truck when it is empty than when it is carrying a heavy load. 3. An engine can exert a force of 1,000 newtons. How fast can this engine accelerate: a. a 1,000- kg car? b. a 2,000- kg car? 4. Use Newton s third law to explain why a blown up but untied balloon will fly around the room when you let it go? 5. Motor oil, axel grease, and other lubricants are slippery. Why do you think people spend the money to put these lubricants in their cars?