The reason we have periods of darkness that we call night is because

Compare the theories that scientists proposed about the source of the sun's energy with the process of nuclear fusion in the sun

How do waves interact with water?

Kent throws a tennis ball that has a mass of 3.0 kg straight up in the air at 25 m/s. What height does it reach if the kinetic energy of the ball is 100% transferred into potential energy at the top of the throw

When an ambulance drives by your house with sirens blaring, the sound waves of the sirens are (space) as it approaches and (space) as it sppeds away

A spring-loaded toy gun is used to launch a 12.0-g plastic ball. The spring which has a spring constant of 15.0 N/m is compressed 8.00 cm as the ball is pushed into the barrell.

One of the main reasons steel is used more widely than iron is because it's lighter softer stronger than iron

What is the frequency of a wave with a velocity of 21.2 m/s and a wavelength of 8.3m?

Positive ions have blank protons than electrons

What is the weight, in n, of an object with a mass of 200 kg at a location where g = 9.6 m/s2. round the final answer to the nearest whole number?

A 1.7 kg book is lying on a 0.77 m - high table. You pick it up and place it on a bookshelf 2.0 m above the floor. how much work does gravity do on the book?