Use the table below to identify four substances that undergo a physical change if the temperature is reduced from 50oc to - 50oc. what is the physical change that takes place in each case.

When will the earths core overheat and explode from the pressure buildup?

A floating boat has a weight of 100 N. What is the buoyant force on the boat?

List three factors that can pollute water.

In 1650, an individual calculated that the earth was about 6,000 years old. since then what has happened to scientists of the earths age? A. scientists now beleive the earth is much younger. B. scientists are now less sure of the earths age C.

Explain why squeezing a plastic mustard bottle forces mustard out to top.

What causes day and night on earth?

A yo-yo can be thought of as a solid cylinder of mass m and radius r that has a light string wrapped around its circumference (see below). One end of the string is held fixed in space.

Why is time an independent variable and position is a dependent variable in a position versus time graph

A geologist estimates that a large boulder weighs 7840 N. What should he estimate the mass of this boulder to be? A. 650 kg B. 740 kg C. 780 kg D. 800 kg

Two objects have the same momentum. Do the velocities of these objects necessarily have (a) the same directions and (b) the same magnitudes? Give your reasoning in each case.