An electromagnetic wave of frequency 10^21 Hz is best classified as _.

A. a gamma ray

B. a radio wave

C. Visible light

D. a microwave

why are the surface features of the moon essentially unaltered since youth

An 80-kgkg quarterback jumps straight up in the air right before throwing a 0.43-kgkg football horizontally at 15 m/sm/s. How fast will he be moving backward just after releasing the ball?

Kevin is standing outside a railway station. He can know whether a train is approaching the station or departing from the sound it makes. Which principle of sound waves is he using?

In what type of change is matter not destroyed

Consider a line of children. While the line of children is rotating, which of the following statements are correct? Check all that apply. a) The player at the front of the line has the smallest angular acceleration.

Which of the following describes the flow of charges through a wire or a conductor?

What is the kinetic energy of a 2 kg snowball thrown through the air at 5 m/s?

A 5.00*105-kg subway train is brought to a stop from a speed of 0.500 m/s in 0.400 m by a large spring bumper at the end of its track. what is the force constant k of the spring

A moving object always has energy in its?

What is the volume of a box that is 12 cm long, 2 cm wide, and 3 cm high?