Key Concepts:
* Newton's First Law of Motion (Inertia): 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.
* Constant Speed: If an object is moving at a constant speed, its velocity is not changing.
* Acceleration: Acceleration is the rate of change of velocity.
Explanation:
Since the crate is moving at a constant speed, its velocity is not changing. This means its acceleration is zero.
Why is the crate moving if the acceleration is zero?
The crate is moving because an external force is being applied to overcome friction. Here's how it works:
1. Friction: There is friction between the crate and the floor. This friction force opposes the motion of the crate.
2. Applied Force: The person pushing the crate is applying a force to counteract the friction.
3. Balanced Forces: The applied force is equal and opposite to the friction force. This means the net force on the crate is zero.
4. Zero Acceleration: Since the net force is zero, the crate's acceleration is also zero.
In Summary: The crate is moving at a constant speed because the forces acting on it are balanced. This results in zero acceleration.
