An electron in the n = 7 level of the hydrogen atom relaxes to a lower energy level, emitting light of 397 nm. what is the value of n for the level to which the electron relaxed?

A ball is thrown straight up. What can be said about the sign of work done by the force exerted by gravity while the ball moves up and then down?

How long will it take an object to move 100 meters if the object is traveling with an average speed of 0.5 meter per second? O 50s o 200 s o 5s 02s

Why did you test the resistance of the wire? A. The current flowing through the lightbulb was too low. Decreasing resistance would increase the current. B. The current flowing through the lightbulb was too high.

An automobile engine delivers 55.0 hp. How much time will it take for the engine to do 6.22 * 105 J of work? One horsepower is equal to 746 watts. Answer in units of s.

1. How much force is required to accelerate a 2 kg mass at 3 m/s?

How would you describe the two projectors used to screen a three-dimensional movie? A. Both projectors have vertical polarizers. B. One projector has a vertical polarizer and the other has a horizontal polarizer. C.

A roller coaster has a mass of 500 kg. It drops from rest at the top of a hill that's 57 m tall. How fast is it going when it reaches the bottom? Acceleration due to gravity is g = 9.8 m/s2.

Two sinusoidal waves are moving through a medium in the positive x-direction, both having amplitudes of 7.00 cm, a wave number of k=3.00m-1, an angular frequency of ω=2.50s-1, and a period of 6.00 s, but one has a phase shift of an angle ϕ=π12rad.

For a vacation, you and your family fly east to west from Boston, Massachusetts, to Seattle, Washington. You notice that your flight back home to Boston is shorter than your flight to Seattle. Which phenomenon causes your flight home to be shorter?

You spy on an anchor on the bottom of a lake. What is the direction and amount of force the water exerts on it: a) zero b) up, equal to the weight of the anchor. c) up, less than the weight of the anchor d) down, equal to the weight of the anchor.