Forces and Motion Flashcards
Can forces be seen?
No, but the effect of forces can be seen.
How many objects are required for a force to be applied?
Two
What are 3 effects can a force have on an object?
It can change the shape of an object or it can change the object’s motion (speed and/or direction).
What does the word ‘Motion’ refer to in physics?
The speed and/or direction of an object.
In what 3 ways can a force deform (change the shape) of an object?
Compress (squash)
Extend (stretch)
Bend / twist
In what 4 ways can a force change the motion of an object?
Increase speed (accelerate)
Decrease speed (decelerate)
Maintain constant speed
Change direction
All forces come in pairs. What can be said about the two forces in a force pair?
They are the same type of force.
They are the same size.
They act in opposite directions.
They act on different objects
Complete the following statement about two forces in a force pair:
A pencil pushes down on a piece of paper, the paper pushes…
A pencil pushes down on a piece of paper.
The paper pushes up on the pencil.
Complete the following statement about two forces in a force pair:
A jet pushes exhaust gases backwards…
A jet pushes exhaust gases backwards.
The exhaust gases push the jet forwards.
Complete the following statement about two forces in a force pair:
The Earth pulls down on the Moon due to gravity…
The Earth pulls down on the Moon due to gravity.
The Moon pulls up on Earth due to gravity.
What do we call forces that can be applied at a distance, even when objects are not touching?
Non-contact forces
What do we call forces that require objects to be touching to be applied?
Contact force
Name the three non-contact forces.
Magnetic
Electrostatic
Gravitational (Weight)
Describe: Applied force
A person pushing or pulling an object.
Describe: Tension
A force in a rope or cable being pulled.
Describe: Reaction force
Force from a surface that opposes an action upon it.
Describe: Friction
A force between two surfaces that opposes motion.
Describe: Drag
A force that opposes motion in fluids (liquids and gases).
Describe: Air resistance
A force that opposes motion in air.
Describe: Water resistance
A force that opposes motion in water.
Describe: Weight
Downwards force due to gravity
Describe: Upthrust
The upwards force of water on a (floating) object.
Describe: Lift
The upwards force that stops aeroplanes falling to Earth.
Describe: Normal contact force
The name of the force that stops objects falling through solid objects.
Describe: Spring force
Force a deformed object exerts against the object that changes its shape.
Is air resistance a contact or non-contact force?
Contact force - air particles must touch an object to exert the force.
What units are forces measured in?
Newtons (N)
What do we draw to show the forces acting on an object?
A force diagram
On a force diagram, what shape is used to represent a force.
An arrow.