What is the Doppler effect?

What do lenses do? A:reflect light B:refract light C:concave mirror D: interfere with light

A ball is rolling a 4 m/s across the floor it hits a pillow and comes to a stop in 1 seconds. What is the ball's acceleration?

For each of the following chemical reactions, calculate the mass of the underlined reactant that is required to produce 1.000 g of the underlined product.

The conventional direction of magnetic field lines outside a magnet are from

Use the Work-Energy Theorem to show that an object with initial velocity vo will travel a distance d across a rough horizontal surface before stopping, where d = vo2 / (2mKg).

A toll booth on a turnpike is open from 8:00 AM until midnight. Vehicles start arriving at 7:45 AM at a uniform rate of 6 veh/min. At 8:15 AM the rate drops to 2 veh/min.

A tornado lifts a truck 252 m above the ground. As the storm continues, the tornado throws the truck horizontally. It lands 560 m away from where it was picked up.

The force of attraction between 2 objects is called gravity. Why do you think that an object, like your notebook, pulled towards you? Explain your reasoning. I don't need the answer I just don't understand what this question is asking.

Two planes leave wichita at noon. One planes flies east 30m/h faster than the other plane, flying east at what time will they be 1200 mi apart?

Red, blue, and green are called a __ __ __ __ __ __ __ primary colors because when they are added together, they form all of the colors of the spectrum.