Jack tries to place magnets on his refrigerator at home, but they won’t stick. what could be the reason?

the body of the refrigerator isn’t made of magnetic material.
earth’s magnetic field is interfering.
the magnet and the body of the refrigerator have like poles.
the refrigerator isn’t plugged into an electrical outlet.

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below. your friend goes first, and you follow after he has dropped a distance of 2.0m. when your friend hits the water, is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.

Explain how the energy of rubber ball is tranforned as it roll down a ramp. give evidence that the energy of the og the ball remains the same at all points on the ramp

What is the orbital period of a spacecraft in a low orbit near the surface of mars? the radius of mars is 3.4×106m.