Forces And Statics Flashcards
(23 cards)
What is a vector quantity?
When something has direction and magnitude.
What is a scalar quantity?
When something only has magnitude.
What are the two main categories of forces?
Contact Forces
Non-Contact Forces
What are non-contact forces?
One object can exert a force on another without even touching it. With all non-contact forces, the closer the objects, the stronger the force.
What are the three non-contact forces?
Electrostatic
Gravitational Force
Magnetic Force
What are contact forces?
When an object exerts a force on another with touching.
What are the five contact forces?
Reaction / Normal contact force
Tension
Friction
Drag (air and water resistance)
Upthrust
What apparatus do you use to measure the force needed?
Newtonmeter
Why does weight change on different planets?
Because different planets have different gravitational field strengths.
Why does mass not change on different planets.
Mass never changes because it is the amount of matter.
What is the equation for weight?
weight = mass x gravitational field strength
w=mg
What are the units for gravitational field strength?
Newtons/Kilogram
N/Kg
What are the units for mass when calculating weight?
Kilograms
What is the gravitational field strength on earth? (For GCSE)
10 N/Kg
What are balanced forces?
If two forces are equal in size but act in opposite directions they are balanced. The resultant force is 0, and the object will be stationary or travelling at a steady speed.
What are unbalanced forces?
There must be a stronger force acting on the object, and can change its speed, direction or shape.
How can you tell if the forces on an object are balanced?
If the resultant force is 0.
What is Newton’s first law of motion?
An object will remain at rest, or moving, continue at a constant velocity unless acted upon by a resultant force.
What is Newton’s second law of motion?
If a resultant force acts on an object, it will accelerate in the direction of the resultant force according to the equation F=ma
What is the resultant force?
The vector sum of all forces acting on the object. (the result of adding all the forces acting on an object, taking the direction into account)
What is the equation that links mass, acceleration and force?
Force = mass x acceleration
F=ma
What are the units for acceleration?
Metres per second per second
m/s/s OR m/s²
