Newtons laws of motion Flashcards
(22 cards)
What is the first law of motion?
An object will keep moving with the same speed and direction unless acted on by a net force.
Objects can be moving or at rest.
What is inertia?
Natural tendency of an object to maintain its velocity and resist any change to speed or direction.
(Inertia is not a force)
What is a net force?
The total force acting on a single object.
Net force on an object with balanced forces is zero as they cancel out.
How do you find a net force?
Add any forces acting in the same direction and subtract any forces acting in opposite directions.
how are the units for force and net force measured?
Newtons (N)
What is the second law of motion?
net force on an object = mass x acceleration.
Mass = force/acceleration
acceleration = force/mass
What is the third law of motion?
Every force has an equal and opposite reaction force.
A exerts a force on B, B exerts an equal force of the same type back on A.
What are force pairs?
Act on different objects
Equal in size
Have opposite directions
Are of the same type
What are balanced and unbalanced forces?
Balanced: Force with an equal and opposite force acting on the same object.
<—- —->
-100N +100N
Unbalanced: Force without an equal and opposite force acting on the same object.
<—- ——–>
-50N +100N
What is gravity and the third law?
No matter how different the mass of two objects, the two gravitational forces will be equal due to newtons third law.
How do you label a force?
F
Force type, x on y
What is acceleration?
Any change in velocity.
Measured in metres per second per second (m/s/s)
What is friction?
Force that resists an objects motion (contact force)
What is velocity?
Speed and direction of an object’s movement.
Objects don’t change velocity without reason.
What is water resistance?
Force that resists an objects movement through water. (contact force)
What is air resistance?
Force that resists objects motion through air. (contact force)
What is a force?
A push or pull. Causes an object to accelerate unless balanced by an equal and opposite force.
What is a free body diagram?
Representation of all forces (represented as arrows) acting on an object (represented as a box)
What is a non-contact and contact force?
Contact force: Any force that can only occur when two objects are touching.
(Air resistance, water resistance, friction, collision force, applied forces)
Non-Contact force: Any force that can occur even when two objects are not touching.
(gravity, magnetism, electrostatic forces)
What is applied force?
A type of force exerted by a person, animal or machine. (contact force)
What is collision force?
A force that acts on an object when it hits another object. (contact force)
What is gravity?
Attractive force between any two objects that have mass.
Force of gravity depends on the size of the masses and the distance between them.
(non-contact force)
