Physics- Forces Flashcards
What is a force?
A force is a push or pull between two objects. Forces also have a size and direction.
What are contact forces? What examples are there of contact forces?
A contact force is a force that acts on objects only when objects touch each other. Examples include friction, air resistance etc.
What are non-contact forces? What examples are there of non-contact forces?
Non-contact forces are forces where objects don’t have to touch for the forces to act on it. Examples include the force of gravity, magnetic force etc.
What does a free-body diagram show?
A free body diagram shows the size and directions of the forces acting on an object.
What are Newton’s laws of motion?
Newton’s 1st law: a particle will remain stationary or will continue to move with constant velocity in a straight line unless acted on by a resultant force. Newton’s 2nd law: F=ma, force (N) = mass (kg) x acceleration (m/s²). Newton’s 3rd law: every action has an equal and opposite reaction.
What is force measured in and measured by?
Force is measured in Newtons and to measure force, we use a Newtonmeter.
What is Hooke’s law
f=kx
Force applied = spring constant x extension of spring
What is terminal speed/ velocity?
Terminal speed/ velocity describes the point when the forces acting on an object become equal and opposite and therefore have a resultant force of 0N.
What is a resultant force?
The resultant force is a single force that has the same effect as all the forces acting on an object.
What happens if the resultant force on an object is zero?
It means the forces acting on the object are balanced. It also means that the object is stationary or moving at a constant velocity.
What happens if the resultant force on an object is greater than zero?
It means the forces acting on the object are unbalanced. It also means that the object will change its speed or direction.
How do you calculate the resultant force when the object is acted on by two forces along the same line?
Their sum, if the forces act in the same directions. Their difference, if the forces act in opposite directions.
