Safety in Science — Unit test Answers

Ricardo is on vacation, doing some mountain climbing. He notices that the higher he goes up a mountain, the colder he feels. He remembers his physics teacher teaching about these types of relationships.

Ricardo wants to determine the length of a strip of zinc metal. What is the SI unit for length?

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Read the lab procedure for a controlled experiment that looks at the effect of heat on the circumference of bicycle tires.Step 1: Pump up six identical bike tires to the recommended air pressure.Step 2: Place three tires under heat lamps, and keep the other three tires at room temperature.Step 3: After four hours, measure the circumference of each tire. Step 4: Record your results in the table.Step 5: (?)Which step should be next in this procedure?

For centuries after Isaac Newton studied gravity, scientists accepted that gravity only exists between two objects that each have mass. However, new observations in the early twentieth century showed that even though light has no mass, it bends toward a planet as though it is forced by gravity. Albert Einstein used this observation, along with mathematical reasoning and many other observations, to redefine gravity and explain why both light and matter experience gravity’s effects. Einstein’s idea predicted many complex behaviors of nature that were later discovered, and because his idea consistently explains so many different observations it is now the basis for much of modern physics.