Does observing a physical property of a substance change the identity of the

substance? Explain your answer.

Why does the bottom of a swimming pool always appear shallower than it actually is

You are standing outside during the daytime. How can you see a blade of grass? A. Light is produced by your eyes and travels out to the grass. B. Light is produced by the grass and travels straight to your eyes. C.

An astronaut wants to test a pendulum clock and takes it on a trip orbiting the earth. What do you expect him to find out?

A small squishy ball is thrown against the side of a large cube of concrete. While the objects are in contact with each other, which experiences the larger force?

What type of star is Sirius B

Is cell using oxygen to break down sugar a physical or chemical change

Which is a branch of Earth science? physics ecology chemistry geology

A 6,600 kg train car moving at + 2.0 m/s bumps into and locks together with one of mass 5,400 kg moving at - 3.0 m/s. What is their final velocity? A.) - 1.0 m/s B.) + 2.5 m/s C.) - 0.25 m/s D.) + 0.50 m/s

Why does matter absorb sound energy?

What is the speed of a wave if the wave length is 100 m and the period is 20 s? A. 80 m/s B. 120 m/s C. 2,000 m/s D. 5 m/s