What Determines a Ball's Motion

* Inertia: A ball at rest wants to stay at rest, and a ball in motion wants to stay in motion at the same speed and in the same direction. This is called inertia.

* Forces: Forces are pushes or pulls that can change an object's motion. They can make a ball start moving, stop moving, change direction, or change speed.

Forces that Change a Ball's Motion

Here are some common forces that affect a ball:

* Gravity: Pulls the ball downwards, making it fall towards the Earth.

* Friction: Acts against the ball's motion, slowing it down. This can be friction from the air (air resistance) or friction from the surface the ball is rolling on.

* Applied Force: This is a force we directly apply to the ball. Think of kicking a ball, throwing a ball, or hitting a ball with a bat.

* Normal Force: The force that a surface exerts on an object, preventing it from falling through the surface.

Examples of Changes in Motion

* Throwing a Ball: You apply a force to the ball, causing it to change from rest to motion.

* Rolling a Ball: The initial force you give the ball is overcome by friction, causing the ball to slow down and eventually stop.

* Bouncing a Ball: The ball hits the ground, and the force of the ground pushes back, changing the ball's direction and making it bounce up.

Key Concepts

* Net Force: The overall effect of all the forces acting on an object. If the net force is zero, the object's motion doesn't change. If the net force is not zero, the object's motion will change.

* Acceleration: A change in velocity (speed and/or direction) over time. Forces cause acceleration.

Let me know if you'd like more details or examples about how a ball's motion can change!