William Heathcote Solutions for Chapter: Consequences, Exercise 11: Summative assessment

 When testing an electric car, engineers drive it at different speeds and measure the current that the motor draws from the battery at that speed.Describe the trend of the data.

When testing an electric car, engineers drive it at different speeds and measure the current that the motor draws from the battery at that speed. Their results are shown in the graph. Suppose the engineers had tested the car on a slight uphill slope. Draw a line on the copy of the graph to show how their results would have differed. Explain your answer.

When testing an electric car, engineers drive it at different speeds and measure the current that the motor draws from the battery at that speed. Their results are shown in the graph. If the maximum current that the battery can deliver is $300 A$, determine the fastest speed that the car can go on a flat road. Give your answer in kilometers per hour.

A team of engineers is going to test electric cars made by three competing companies, and they intend to publish their results. The car companies believe that it is important that the results of the tests are reliable and fair. Explain what the engineers should do to ensure that their results are reliable and fair.

Electric cars are an alternative method of transport to petrol-and diesel-powered cars. One disadvantage of electric cars is that they are so quiet that they are not easily heard. It is argued that this makes them more dangerous to pedestrians. One solution is to connect a loudspeaker to the battery so that the car makes more noise. A scientist on the design team for an electric car points out that the battery is a d.c. supply, so the loudspeaker would not be able to generate a sound. Instead, the scientist proposes that a circuit that generates an alternating current at a certain frequency should be used. Write an explanation that the scientist might use to persuade the rest of the design team that a .c. current should be used and suggest a suitable frequency. Try to use simple scientific terms effectively.

Apart from the noise issue, describe one advantage and one disadvantage of electric cars over petrol and diesel cars.

Electric cars are a solution to the problem of how to get from one place to another. Give one alternative method of getting from one place to another and describe an advantage and a disadvantage compared to a  car. 

People travel more today than they did $100$ years ago. Discuss whether modern society and technology require people to travel more or not.