Which statement accurately classifies helium? a. it is an atom b. it is a mixture c. it is a molecule d. it is a compound

Prompta snowboarder stands at the top of a hill and decides to see if he can increase his speed on his next trip down the slope.describe one thing the snowboarder could do to incrlase his speed on the slope. explain why this would cause his speed toincrease relate one of newton's laws to this problem.

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?