A child rides their sled at a constant speed down an hill. There is friction between the ground and the sled.

Astronauts in orbit feel weightlessness because, choose all that apply.   A. astronauts in orbit are without support force.   B. Because of absence of gravity in orbit.   C. astronauts in orbit are in a state of continuous free fall.   D. Orbits are designed like that so that there is no force.

a. An object that is free-falling is acted upon by the force of gravity alone. b. A falling skydiver which has reached terminal velocity is considered to be in a state offree fall. c. A ball is thrown upwards and is rising towards its peak. As it rises upwards, it is NOT considered to be in a state offree fall d. An object in free fall experiences an acceleration which is independent of the mass of the object. e. A ball is thrown upwards, rises to its peak and eventually falls back to the original height. As the ball rises, its acceleration is upwards; as it falls, its acceleration is downwards. f. A ball is thrown upwards, rises to its peak and eventually falls back to the original height. The speed at which it is launched equals the speed at which it lands. (Assume negligible air resistance.) g. A very massive object will free fall at the same rate of acceleration as a less massive object.

Why a ball rolling across the floor does slows to a stop? a. The force that started it moving wears out. b. The forces are balanced. C. The net force equals zero d. There is a net force acting on it.

What happens to a car traveling on a spiral path, toward the center, if its speed stays the same the whole time? and why ? a. the acceleration increases b. Its centripetal force gets bigger c.Its centripetal force gets smaller  d.Its acceleration decreases

A worker pulls a crate of mass, m, via a uniform, massless cable that is attached to the crate at an angle, θ, above the horizontal. The resultant tension in the cable is T. What is the normal force acting on the crate? a. mg b. mg + Tsinθ c. mg - Tcosθ d. mg - Tsinθ e. Tsinθ