Why are electromagnets used in metal scrap yards

Aroller coaster car is traveling down a track at 22 m/s. the car has a mass of 2000 kg. what is the kinetic energy of the car? a) 22,000 j b) 968,000 j c) 484,000 j d) 44,000 j

Sum of brother and sisters age is 26. four times the brothers age is subtracted from three times the sisters age, the difference is 8. what are the ages of the brother and sister?

Aplanet similar to earth has four moons roughly the same distance away. the moon that will most affect tides on the planet is the one that has the greatest a) mass. b) volume. c) density. d) amount of water.