* Newton's First Law: 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, it means its *velocity* (speed and direction) isn't changing. This implies that the net force acting on it must be zero.
Think of it this way:
Imagine you're pushing a box across a smooth floor at a steady pace. You're applying a force to move the box, but there's also friction opposing your push. If the box is moving at a constant speed, it means your push force and the friction force are perfectly balanced, resulting in a net force of zero.
What you need to know to find net force:
* Acceleration: Net force is directly related to acceleration (change in velocity) through Newton's Second Law: F = ma. If the object's speed is constant, its acceleration is zero, and therefore the net force is also zero.
Example:
Let's say a car with a mass of 1000 kg is traveling at a constant speed of 20 m/s. Since the speed is constant, the acceleration is 0 m/s². Therefore, the net force acting on the car is:
F = ma = (1000 kg) * (0 m/s²) = 0 N (Newtons)
In summary: Constant speed implies zero acceleration, and zero acceleration means zero net force.
