A surfer gets faster as he travels through a large wave are the forces on the surfer balanced or unbalanced how do you know

Janelle made a hypothesis bout the uneven temperatures inside her house during winter. she believes that 50% of the ducts are blocked and she plans to investigate. if she wants to prove her hypothesis using scientific processes what should she do next?

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

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.