* Acceleration is a change in velocity. Velocity has two components: speed and direction.
* Acceleration can change either the speed or the direction of motion.
Here are some classic examples:
* Projectile motion: Think of a ball thrown horizontally. It has an initial horizontal velocity. Gravity acts as a downward acceleration, changing the ball's vertical velocity. The ball travels in a curved path, even though the acceleration is perpendicular to the initial motion.
* Circular motion: Imagine a car going around a circular track at a constant speed. The car's velocity is constantly changing direction, even though its speed is constant. This change in direction is caused by an acceleration towards the center of the circle (called centripetal acceleration), which is perpendicular to the car's motion at any given moment.
* A satellite in orbit: A satellite orbiting Earth experiences a constant acceleration towards the Earth's center, keeping it in its circular path. This acceleration is perpendicular to the satellite's velocity, which is tangential to the orbit.
In essence, if an object experiences acceleration perpendicular to its current motion, it will change direction. The object will continue moving in its original direction but will also start curving in the direction of the acceleration.
