Topic 5+6-Forces and Waves Flashcards
What are the two types of quantities?
- Scalar.
- Vector.
What quantity is force?
Vector.
What quantity is speed?
Scalar.
What is a scalar quantity?
Something that only has a magnitude but no direction.
What is a vector quantity?
Something that has a magnitude and a direction.
All forces are…
Contact or non-contact.
What is an interaction pair?
A pair of forces that are equal and opposite and act on two interacting objects.
What is the equation for weight?
mass x gravitational field strength.
Are mass and weight directly or indirectly proportional?
Directly proportional.
What do free body diagrams show?
All the forces acting on an object.
What is meant by the resultant force?
The overall force on a point or object.
What is the equation for work done?
Force x distance.
When is an object in equilibrium?
When all of the forces add together to equal zero.
What are objects that have been elastically deformed called?
Elastic objects.
What does it mean if an object has been elastically deformed?
It can go back to its original shape and length after a force has been removed.
What is the equation for force?
Spring constant x extension.
What is the equation for a moment of a force?
Force x distance.
What is the equation for pressure?
Force over area of surface.
What is meant by density?
How close the particles are together in a substance.
If the upthrust is equal to an objects weight…
The object will float.
What is atmospheric pressure caused by?
Air molecules colliding with the surface of the earth.
As the altitude increases what happens to the atmospheric pressure?
It decreases.
Why does the atmospheric pressure decrease with higher altitude?
Because less particles are able to collide with the surface of he earth.
What is the typical speed of a person walking? (idk why we need to know this but it says we do)
1.5 m/s
What is the typical speed of a car?
25 m/s
What is acceleration?
The change in speed over time.
What direction does friction always act?
In the opposite direction to movement.
What is drag?
The resistance you get in a fluid.