# Xplain Which Forces Are Balanced Physics Homework Help

1. A baseball is thrown straight upward. Describe the direction and magnitude of the velocity, force of gravity, and the varying air resistance force as the ball rises. Explain whether the net force increases, decreases, or is unaffected by the air resistance force. Repeat for the part of the motion when the ball is at maximum height and the part of the motion when the ball is moving downward.
2. A ball is thrown horizontally from a platform so that the initial height of the ball is 6.0 m above the level ground below. The ball lands 24 m from its original horizontal location. Find how fast the ball was thrown. Show all work.
3. A car is driven at constant velocity along a level highway. Indicate the value of the net force and list all the main forces acting on the car to produce the net force. Clearly explain what produces or exerts each of the contact forces acting on the car and explain which forces are balanced.
4. Summarize two observations that are contrary to the predictions based on Newton’s laws but that confirm Einstein’s explanation of gravity. Indicate how the predictions based on Newton’s theory differ from Einstein’s.