Practice: Which of the following quantities are constant during projectile motion?

Concept #1: Introduction to Projectile Motion

Practice: Which of the following quantities are constant during projectile motion?

Concept #2: Solving Horizontal Launch Problems

Practice: A rock is thrown horizontally with a speed of 20 m/s from the edge of a high cliff. It lands 80 m from the cliff's base. How tall is the cliff?

Example #1: A ping-pong player standing 1.6 m from the net serves the ball horizontally. The ball is hit 1.2 m above the floor. What initial speed does the ball need to go over the net, which is 1.6m away from the player and 0.90m above the floor?

Example #2: You kick a ball horizontally at 8 m/s from the roof of a 40m-tall building. Unfortunately, a car below you on the street accelerates forwards from rest, and your ball lands on the car. What was the acceleration of the car (assumed to be constant)?