I know what dark matter is, but what exactly is dark energy and what does it do?

What are two different ways to understand time? Explain and give example?

A car goes from 80 km/h to 20 km/h in 0.5 h. What is the acceleration in km/h squared?

Find the net gravitational force fnet acting on the earth in the sun-earth-moon system during the new moon (when the moon is located directly between the earth and the sun. express your answer in newtons to three significant figures.

Mention two ways to increase the strength of an electro magnet.

A substance that protects cells from being damaged by oxidation

A 0.8kg object accelerate at a rate of4 m/s2. What is the net force acting on a object

Which of the following is the best definition of an isotope? A. elements of the same kind with different numbers of neutrons B. elements of the same kind that have lost electrons C. elements of the same kind that have different electrical charges

Two cars approach each other; both cars are moving westward, one at 85 km/h, the other at 54 km/h. what is the magnitude of the velocity of the first car relative to (in the frame of reference of) the second car? answer in units of km/h.

What usually causes high concentration of minerals to form

The courtroom role that possesses the most discretion is?