State two uses of total internal reflection

Why does the moon appear to change shape? A: It rotates and makes it own light B: It moves closer and farther away from the earth in a yearly pattern. C: It reflects sunlight as it revolves around the earth.

A 20.0 g marble moving to the right at 28.0 cm/s overtakes and collides with a 19.0 g marble moving in the same direction at 16.0 cm/s. After the collision, the 19.0 g marble moves to the right at 24.3 cm/s. Find the velocity of the 20.

What is the range of these data? 6,9,2,12,3,5,9

Suppose a wave carries 3 units of energy and has an amplitude value of 2. If you double the amplitude to 4, how many units of energy will the wave now carry? A. 3 B. 6 C. 9 D. 12 ... ?

Which statements about velocity is true A. The symbol for velocity is v B. For velocity you must have a number, a unit and direction. C. To calculate velocity, divide the displacement by time D. The SI unit for velocity are miles per hour

Which of Newton's laws, when combined algebraically with his law of universal gravitation, can be used to calculate Earth's mass? A) first B) second C) third

Why does a balloon filled with helium rise while a balloon filled with an equal volume of average atmospheric air does not? A. Helium has no mass, but air does. B. Helium increases the balloon's mass more than air. C.

Consider the following controls in an automobile in motion : gas pedal, brake, steering wheel. what are the controls in this list that cause an acceleration of the car?

What material are oil pipelines made from?

3/129 A 175-lb pole vaulter carrying a uniform 16-ft, 10-lb pole approaches the jump with a velocity v and manages to barely clear the bar set at a height of 18 ft. As he clears the bar, his velocity and that of the pole are essentially zero.