Forces Flashcards
(37 cards)
What is a vector quantity?
one with a magnitude and a direction
What are some examples of vectors?
- force
- velocity
- displacement
- acceleration
- momentum
What is a scalar quantity?
a physical quantity with only magnitude and no direction
What are some examples of scalars?
- speed
- distance
- mass
- temperature
- time
What are some examples of contact forces?
- friction
- air resistance
- tension in ropes
- normal contact force
What are some examples of non-contact forces?
- magnetic force
- gravitational force
- electrostatic force
What is an interaction pair?
a pair of forces that are equal and opposite and act on two interacting objects
What are the two effects of a large gravitational force?
- makes all things fall towards the ground
- gives everything a weight
What is gravitational force?
the force of attraction between masses
What is mass?
the amount of ‘stuff’ in an object. For any given object this will have the same value anywhere in the universe.
What is weight?
the force acting on an object due to gravity- close to earth this force is caused by the gravitational field around the earth
What does the weight of an object depend on?
the strength of the gravitational field at the location
What is the gravitational field strength of the earth and the moon?
earth- 1.6 N
moon- 9.8 N
How do you measure the weight of an object?
using a calibrated spring balance or newtonmeter
What is resultant force?
the overall force on a point or object
What does it mean for an object to be elastically deformed?
- if it can go back back to it’s original shape and length after the force has been removed
- if all energy is transferred to the object’s elastic potential energy store
What is a moment?
the turning effect of a force
What effects the size of a moment?
- size of force
- size of distance between force and pivot
How do you get the maximum moment?
you need to push at right angles to the thing giving the moment i.e. spanner
What is the pressure of a fluid?
a force exerted normal to any surface in contact with the fluid
What is density?
a measure of the ‘compactness’ of a substance
Does the pressure of a liquid increase with depth and why?
Yes because the weight of the particles above that point increases so add pressure to that point
What is upthrust?
When the pressure exerted from the bottom of the object is larger than the force acting on top of the object
What does it mean if an object floats in a liquid?
that the weight of the object is equal to it’s upthrust
