You push really hard against a round rock, but you cannot make it roll. Which statement best explains why you cannot move the rock? Gravity pulls the rock toward the center of Earth.
The forces between you and the rock are balanced.
The force of your push is greater than the opposing force.
There is no friction to help you move the object.

Two friends are having a conversation. anna says a satellite in orbit is in freefall because the satellite keeps falling toward earth. tom says a satellite in orbit is not in freefall because the acceleration due to gravity is not 9.80 m/2 . who do you agree with and why?

What is the length x of the side of the triangle below? (hint: use the cosine function)

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.