On what basis are different photons to be distinguished?

A. Their energy levels

B. The atoms they come from

C. Their masses

D. Their speeds

What are the primary colors of visable light

A temperature of 50.0 degrees Celsius is the same as a Kelvin temperature of approximately -223 K 223 K 273 K 323 K

Within which type of water body does water move the slowest? A.) River B.) Cloud C.) Ocean D.) Groundwater

A train approaches a railroad crossing, blowing its whistle the entire time. When does an observer at the crossing hear the lowest frequency of the train's whistle?

What are semi - conductors?

Two copper wires with different diameters are joined end to end. If a current flows in the wire combination, what happens to electrons when they move from the larger-diameter wire into the smaller-diameter wire?

A baseball player is warming up and tosses a ball straight up into the air. The ball travels up until it reaches some maximum height, and then falls back down to the player/'s hand.

Volume can be measured in liters or cubic meters. a. T b. F

A spring with a spring constant of 1200 N/m has a 55-g ball at its end. The energy of the system is 5.5J. What is the amplitude of vibration?

Force F1 acts on a particle and does work W1. Force F2 acts simultaneously on the particle and does work W2. The speed of the particle does not change. Which one of the following must be true? a. W1 is zero, and W2 is positiveb. W1 = - W2c.