Newton's 1st Law
This law is also known as the law of inertia.
What is Newton's First Law of Motion?
This is the equation for Newton's Second Law.
What is F=ma (Force = mass x acceleration)?
For every action, there is an equal and opposite one of these.
What is a reaction?
A free-body diagram shows all of these acting on an object.
What are forces?
This is the unit of force in the metric system.
What is a Newton (N)?
An object at rest will stay at rest unless acted upon by this.
What is a net external force?
If you push a 10 kg box with a force of 50 N on a frictionless surface, this will be its acceleration.
What is 5 m/s²?
A rocket moves forward because the exhaust gases push in this direction.
What is backward?
In a free-body diagram, forces are represented by these.
What are arrows or vectors?
This is the force that opposes motion between two surfaces in contact.
What is friction?
A hockey puck sliding on frictionless ice will continue to move at a constant velocity because of this property.
What is inertia?
To accelerate a 1000 kg car at 2 m/s², you need this much net force.
What is 2000 N?
When you jump, you push down on the Earth, and the Earth pushes you in this direction.
What is up?
A box is at rest on a table. The free-body diagram would show these two forces.
What are gravity (down) and the normal force (up)?
This is the force of gravity on an object.
What is weight?
If the net force on an object is zero, its acceleration will be this.
What is zero?
A 5 kg object accelerates at 3 m/s². This is the net force acting on it.
What is 15 N?
A book resting on a table exerts a downward force on the table. The table exerts this kind of force on the book.
What is an equal and opposite (upward) force?
An object in equilibrium has a net force of this.
What is zero?
An object with more mass has more of this.
What is inertia?
A car is moving at a constant velocity of 50 mph. This is the net force acting on the car.
What is zero?
If you double the net force on an object, its acceleration will do this.
What is double?
A bug hits a car's windshield. This is the relationship between the force the bug exerts on the car and the force the car exerts on the bug.
What is that the forces are equal in magnitude and opposite in direction?
A car is accelerating to the right. The free-body diagram must show a net force in this direction.
What is to the right?
When an object is in free fall, this is the only force acting on it. (air resistance is negligible)
What is gravity?