Imagine a young woman named Sarah is driving her car down a highway at a constant speed of 60 mph. Suddenly, she sees a deer darting across the road ahead.
Here's where the law of acceleration comes in:
* Initial State: Sarah's car is moving at a constant speed of 60 mph. This means her car has a velocity of 60 mph, but her acceleration is 0.
* Change in State: Sarah slams on the brakes to avoid hitting the deer. This action causes a change in her car's velocity. The car slows down, indicating a decrease in velocity.
* Acceleration: Because Sarah's car is undergoing a change in velocity (slowing down), it is experiencing deceleration. Deceleration is simply negative acceleration, meaning the car's velocity is decreasing.
Therefore, Sarah's car is experiencing acceleration (deceleration) due to the force of the brakes.
This example demonstrates the law of acceleration: An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
In this case, the force of the brakes is the unbalanced force that causes the car to decelerate (slow down) and change its velocity.
