Question

researchers testing solar - powered cars... equally well when they are exposed to two hours of sunlight as when they are exposed to four hours of sunlight. which of the following is a piece of evidence that best supports the conclusion? eight out of ten cars that were exposed to two hours of sunlight moved as quickly and drove as long as the cars exposed to four hours of sunlight. seven out of ten cars had the same size solar panels. when the cars were exposed to two hours of sunlight, their batteries were fully charged. all the solar - powered cars were able to reach speeds between 40 and 60 miles per hour (96.56 km/h).

Explanation:

The conclusion is that solar - powered cars perform equally well with 2 hours and 4 hours of sunlight. We need to find evidence that supports this.

• For the first option: Eight out of ten cars exposed to 2 hours of sunlight moved as quickly and drove as long as those exposed to 4 hours. This directly compares the performance (speed and driving duration) of cars with different sunlight exposure times and shows they are similar, supporting the conclusion.
• The second option (seven out of ten cars having the same size solar panels) is about the solar panel size, not the relationship between sunlight exposure time and car performance, so it doesn't support the conclusion.
• The third option (batteries fully charged with 2 hours of sunlight) only talks about 2 - hour exposure and doesn't compare it with 4 - hour exposure, so it can't support the conclusion about equal performance.
• The fourth option (all cars reaching speeds between 40 - 60 mph) is about the general speed range of all cars, not the comparison between 2 - hour and 4 - hour sunlight exposure, so it doesn't support the conclusion.

Answer:

Eight out of ten cars that were exposed to two hours of sunlight moved as quickly and drove as long as the cars exposed to four hours of sunlight.