P9 - Forces Flashcards
What is a scalar?
Quantities that only have a magnitude
What is a vector?
Quantities that have a magnitude and a direction
What are forces?
A push or pull on an object caused by an interaction with another object. Forces are vector quantities
What is a contact force?
When two objects are touching each other (e.g. friction, air-resistance and normal contact force)
What is a non-contact force?
Forces that act at a distance, without touching (e.g. gravitational force and magnetic force)
What is a free body diagram?
A diagram that uses arrows to show all of the forces acting on a single object.
What is deformation?
A change in the shape of an object caused by stretching, squashing, bending, or twisting
What is elastic deformation?
When the object can go back to its original shape and size when the forces are removed
What is inelastic deformation?
When an object does not go back to its original shape or size when the forces are removed
How do you calculate the spring constant?
Spring constant = force applied ÷ extension
N/m = N ÷ m
How do you calculate a moment?
moment of force = force x distance
M = Fd
What do you call it when an objects clockwise moments = its anticlockwise moments
Balanced
What can gears and levers do?
Increase the moment of a force, making it easier to lift or rotate and object
What is the limit of proportionality
The point beyond which Hooke’s Law is no longer valid for a material
