For an object to be in projectile motion, what force must be acting on it

A 0.060 kg ball hits the ground with a speed of - 32 m/s. The ball is in contact with the ground for 45 milliseconds and the ground exerts a + 55 N force on the ball. What is the magnitude of the velocity after it hits the ground?

Which of the following is false regarding the laws of physics in the universe? Energy is always conserved. Momentum is always conserved. Charge is always conserved. Entropy is always conserved. All of the above are true.

A student throws a baseball horizontally at 25 meters per second from a cliff 45 meters above the level ground. Approximately how far from the base of the cliff does the ball hit the ground? [neglect air resistance.]

Dr. Lao has discovered a substance that emits energy in the form of waves. If Dr. Lao observes that these waves can travel through a perfect vacuum, then

Why might a food processing company employ a team of scientists? A) to manage the day-to-day running of the company B) to ensure that the products are safe to consume C) to supervise the production process of food items D) to ensure that the raw

A solid sphere of radius R has a total charge Q distributed evenly throughout its volume. What fraction of the total charge is located inside a radius R/2?

What is Nothing. (sorry i have been wondering this for a very long time)

What is the speed of a bobsled whose distance-time graph indicates that it traveled 123m in 28s?

Eric has a mass of 80 kgkg. He is standing on a scale in an elevator that is accelerating downward at 1.7 m/s2m/s2. What is the approximate reading on the scale?

Without the force of friction, people would not be able to walk.