When the amount of a radioactive substance is reduced by 50%, what has occurred? a half-life beta radiation alpha radiation gamma radiation?

A light year is approximately 9.5 million km long. 'Barnard's Star' is 6 light years away from Earth. Calculate how many millions of kilometres this is.

The diagram shows two dogs pulling on a rope with constant but unequal forces in which Compass direction will both dogs likely move First dog - - facing east on west side 175 newtons Second dog--facing west on east side 200 newtons

What principle states that any ray of light subjected to reflection or refraction can be traced in reverse by a ray in the opposite direction?

Write an expression for the final momentum (momentum of you shoe after you throw the shoe). Assume you are moving at a speed v. Use m for your total mass (including shoes) and shoe for the mass of the shoe.

A bar magnet is a dipolar. This means is has how many poles

11. Which of the following best explains velocity? A. The direction of an object in motion B. Only the change of direction of an object in motion C. The speed and direction of an object in motion D. The speed of an object in motion

Using 6400 km as the radius of Earth, calculate how high above Earth's surface you would have to be in order to weigh 1/16th of your current weight. Show all work leading to your answer OR describe your solution using 3 - 4 complete sentences.

Which of these could occur if a switch is closed? A. A light bulb will light up. B. A hair dryer will turn off. C. A computer will shut down. D. B and C

When you throw a ball the work you do to accelerate it equals the kinetic energy the ball gains?

Old-fashioned heating systems sent steam into radiators in each room of a house. in the radiators, the steam condensed back to water. analyze this process and explain how it heated a room.