Newton's Law of Motion Flashcards
What is force? What is the symbol and in what units is it measured in?
A force is a push or a pull acting upon an object as a result of its interaction with another object. The symbol for force is F and it is measured in Newtons (N)
What is Newton’s first law? What does it state?
Inertia.
The Law of Inertia states that an object remains at rest or in constant motion in a straight line unless acted on upon by a net unbalanced force.
Why is an everyday object such as an apple stationary when placed on a table?
The apple is stationary because it has the force of gravity (also known as weight force) acting upon the object and pulling it down. However, there is another force equal in magnitude but opposite in direction pushing up on the object from the surface. Because these forces are equal in magnitude and are pushing upon each other, the apple has zero net force. Thus the apple is stationary because it doesn’t have any unbalanced forces acting on it and the force of gravity and force from the surface are balanced.
What is net force? What does zero net force mean?
Net force is the sum of all forces acting upon an object. Zero Net force means that the object HAS NO ACCELERATION (0 ACCELERATION). Zero net force means that an object is stationary or moving at a constant speed.
It is in a state of EQUILIBRIUM
Does zero net force mean that an object is stationary?
Yes, but it can also mean that the object is moving at a constant speed - since there is no acceleration and no forces acting upon it.
The larger the mass of an object, the more inertia it has. True / False?
True
If the net force of an object is zero, then…
The speed of the object is constant because there is no change in acceleration. The speed and direction DO NOT change.
When the net force is zero, the forces of an object are all balanced. True / False?
True
What is a force diagram?
A force diagram represents all the forces acting upon the object. The forces are drawn with arrowheads which show the direction of the force. The length of each line shows the size of each force.
What is a vector diagram?
A vector diagram shows the net force acting on an object, where all the forces are added together, showing the resultant force.
What is friction?
Friction is a force that resists the motion of one object against the other
What is Newton’s second law? What is the formula?
Newton’s second law states that the acceleration of an object is directly proportional to the net force and inversely proportional to the mass of the object.
Force = Mass x Acceleration
F = ma
a = f / m
What is the SI unit for mass?
Kg (Kilograms)
Thus, One Newton = Kg meters per second squared (since F = ma)
What is the difference in mass and weight?
Mass is the amount of matter in an object. But weight is the force of gravity acting upon the object.
Mass does not change in relation to location, but weight does. (such as in space or in a different planet)
What is the formula for weight?
Weight = Mass x Acceleration due to gravity
W = m x g