Chapter 3 Flashcards
5 types of forces
~Weight ~contact force ~friction ~air resistance or drag ~upthrust
Weight force
The weight of an object is the pill of gravity on it, weight always acts vertically downwards
Contact force for
When two objects touch, there is contact force, it is the force that stops you from falling through the floor
Friction
Opposes motion. Think about the direction in which an object is moving (or trying to move)
Friction acts in the opposite direction
Air resistance force
Is the force of friction when an object moves through water or air
Upthrust Force
Is the upward push of a liquid or gas on a object.
Resultant Force
Is the single force that has the same effect as two or more forces
No resultant Force means
It will not accelerate, remaining at rest or constant speed
A = 0
Mass
Is measured in kg, and tells you how much matter it is composed out off
Weight
Of an object = the gravitational force that acts on it
Measured in N
Newton’s
Weight equation
Mass X acceleration of free fall
Or
W = mg
Acceleration due to gravity on earth in grams
= 10m/s^2
What does the gravitational field cause
Objects to fall to the ground because they have weight
Earth is pulling downwards on their mass
An object moving in circles
It will follow the rules of a tangent, always 90*
Force in forward direction and force always towards the middle of the circle
Newton
The force required to give a mass of 1kg an acceleration of 1m/s^2
Force
The action of one body on a second body that causes its velocity to change
Force = mass X Acceleration
F=ma
Quantity, symbol and si unit
Force - F - newton (N)
Mass - M - kilogram, kg
Acceleration - A - Metres per second squared, m/s^2
Scalar quantities
Speed Mass Energy Density Temperature
Vector quantities
Velocity
force
Weight
Acceleration
Force, mass and acceleration
1 Main def in forces
The greater the mass of an object, the smaller the acceleration it is given by a particular force
Terminal velocity
At terminal velocity, the object moves at a steady speed in a constant direction because the resultant force acting on it is zero.
Impulse = momentum
Force x time
Momentum = impulse
Mass x velocity
Gravity
Is the force that exists between any two objects with a mass
10m/s2
Acceleration
Force/mass
