Why does a ball keep rolling until something stops it? Newton's three laws of motion explain exactly how forces change â or don't change â the way things move.
An object at rest stays at rest, and an object in motion stays in motion at constant velocity, unless acted on by a net external force. This tendency to resist a change in motion is called inertia.
Why do passengers in a car lurch forward when the car suddenly brakes?
Due to inertia â their bodies tend to keep moving forward at the car's original speed even as the car itself slows down
The force needed to accelerate an object equals its mass multiplied by its acceleration:
A 5 kg object accelerates at 2 m/s². What force is acting on it?
F = m Ă a = 5 Ă 2 = 10 N
For every action, there is an equal and opposite reaction â when one object exerts a force on a second object, the second object exerts an equal force back in the opposite direction.
When you jump off a small boat onto a dock, why does the boat move backward?
As you push against the boat to jump forward (action), the boat pushes back against you with an equal and opposite force (reaction), sending it backward
1. What is inertia?
2. Using F=ma, find the force needed to accelerate a 10 kg object at 3 m/s².
3. State Newton's Third Law in one sentence.
4. Why does a rocket move upward when gas is pushed out of its engine downward?
5. A 2 kg object experiences a force of 8 N. Find its acceleration using F=ma.