According to Einstein's theory of relativity, how can energy be created?

1. by creating matter

2. by transforming energy into other forms

3. by destroying matter

How many neutrons does element x have if it's atomic number is 23 and it's mass is 90

Ashley decides to go for a walk. She walks 5 blocks west, 2 blocks south, 5 blocks east and finally 2 blocks north. What is the total distance traveled?

Why are noble gases are chemically unreactive?

Two cars are moving in the same direction in parallel lanes along a highway. At some instant, the velocity of car A exceeds the velocity of car B. Does that mean that the acceleration of car A is greater than that of car B? Explain.

A 2500 kg car traveling to the north is slowed down uniformly from an initial velocity of 27.0 m/s by a 7850 N braking force acting opposite the car's motion. What is the car's velocity after 2.52s? How far does the car move during the 2.

A car dropped from a height of 44 meters fall to a height of zero meters. How fast will the car be traveling as it hits the ground? Assume air resistance is negligible (show all work)

A rock dropped from a 20 meter bridge falls into the river below. How long did it take to reach the water? What velocity did it hit the water with.

Which of the following is a characteristic of an electromagnetic wave? A. It travels at the speed of light B. It can be transverse or longitudinal C. It involves displacing a medium in the same direction the wave moves D.

If 50% of a radioactive element remains after 4000years what is the half life

What process is responsible for producing sediments that become the layers of sedimentary rock?