Physics Forces & Energy Flashcards
What is a force?
A push or a pull on an object caused by it interacting with another object.
What is Newtons 1st Law?
If forces are balanced, the object travels at a constant speed
Name some non-contact forces.
Gravitational, magnetic, electrostatic
Name some contact forces.
Friction, tension, NCF, air resistance
What is weight?
The force acting on an object due to gravity.
True or false: Gravity is a force.
False
What is the unit of weight?
Newtons (N)
What is the equation for weight?
W = m x g
(Where g = gravitational field strength)
What unit is gravitational field strength measured in?
N/kg
What is the gravitational field strength of Earth? (2dp)
9.81N/kg
What is Hooke’s Law?
The force exerted on a spring is directly proportional to the extension.
What does directly proportional mean?
As one variable is doubled, so is the other (straight line on a graph through the origin)
What is the equation for Hooke’s Law?
F = ke
What does k mean?
Spring constant
What unit is the spring constant measured in?
N/m
What does ‘e’ mean?
Extension
What is the limit of proportionality?
The point at which the force is not directly proportional to the extension, and is in the plastic region.
What is the ‘plastic region’?
When a spring is past the limit of proportionality and loses elasticity. Once it’s plastic, it’s irreversible.
