If humans only have three kinds of color photo-receptors, how can we see so many different colors?

Which form of energy does the motor convert most of its electric energy into?

Technological design leads to the development and innovation of new technologies. Which statements represent innovation? Check all that apply. Solar panels have increased in efficiency over the past 20 years.

A rope is vibrated so that transverse waves propagate down it. if the distance between crests is 0.5 m and a new crest reaches the end every 0.4 seconds. what is the propagation speed of the wave?

Does our body has cells

The table shows columns that Franklin uses to organize his notes on the properties of elements. His notes state that some elements are widely used in semiconductors.

A raindrop has a mass of 5.4 * 10-7 kg and is falling near the surface of the earth. Calculate the magnitude of the gravitational force exerted (a) on the raindrop by the earth and (b) on the earth by the raindrop.

As an astronaut travels towards Earth, her weight A. decreases because gravity decreases. B. decreases because her mass decreases. C. increases because gravity increases. D. remains the same because her mass remains the same.

Lightning often strikes water. a. True b. False

How much work must be done on a 10 kg snowboard to increase its speed from 4 m/s to 6 m/s?

If a spacecraft that seems to be motionless in deep space is given some type of quick push, what will happen? A. The spacecraft will not move because it only works on earth. B.