P5 Flashcards
what is a force? (2)
- a push or pull that acts on an object due to the interaction with another object
- a vector with a size and direction
what do vector quantities have? What are some examples(5)?
magnitude and direction
- e.g forces, velocity, -displacement, acceleration, momentum etc
What do scalar quantities have?What are some examples(5)?
only magnitude (size)
- e.g - speed, distance, time, temp, mass, etc
what is displacement?
measures distance and direction in a straight line from an object’s starting point to it’s finishing point
what is the difference between mass and weight?
what is the difference between speed and velocity?
speed - how fast you’re going (e.g 30mph or 20m/s)
velocity - speed in a given direction (e.g 30mph, north or 20m/s , 060 degrees)
what is an interaction pair?
a pair of forces that are equal and opposite and act on 2 interaction objects
what are 5 examples of contact forces?
- friction
- air resistance
- normal contact force
- lift
- water resistance
what are 3 examples of non- contact forces?
- gravitational force
- magnetic force
- electrostatic force
what does the gravitational field strength (GFS) varie with?
with location
- GFS is stronger the closer you are to the mass causing the field and is stronger for larger masses
what does the weight of an object depend on?
the strength of the gravitational field at the location of the object
- so weight of object changes with it’s location
what is used to measure weight?
a calibrated spring balance or newtonmeter
what is the resultant force?
the overall force on a point or object
Tne sum of all forces or overall force acting on an object.
what is needed for an object to stretch, compress or bend when a force is applied to it?
more than one force acting on it
- otherwise the object will only move in the direction of the applied force instead of changing shape
when is an object elastically deformed?
when it can revert to it’s original shape and length after the force has been removed
when is an object inelastically deformed?
when it can’t revert to it’s original shape and length after the force has been removed
what is the extension of an elastic object directly proportional to?
the load or force applied
What is limit of proportionality? n.d
what are the typical speeds for theses everyday objects:
- person walking, running, cycling,
- a car, train and aeroplane.
- person walking - 1.5m/s
- person running - 3m/s
- person cycling - 6m/s
- car - 25 m/s
- train - 30 m/s
- plain - 250m/s
what is the speed of sound in air? what is it varied by?
330 m/s
- varies on what sound waves are travelling through and speed of wind
what factors affect wind speed? (3)
- temp
- atmospheric pressure
- large building/ structures nearby
what is acceleration?
the change in velocity in a certain amount of time
- how quickly you speed up
what is uniform acceleration?
speeding up/ slowing down at a constant rate
- constant acceleration
What is drag?
the resistance you get in a fluid (liquid or gas)
- air resistance is a type of drag
What is Hookes Law
A spring will always stretch by a proportional amount when force is increased
- however only applies to the elastic limit
What name is given to the point at which the mass of an object may be considered to be concentrated?
centre of mass
A single force can be resolved into two component forces that act at _____° angles to each other. What number completes the sentence?
90
when an object moves in a circle the __________ of the object is continually changing. What is the missing word in this sentence?
velocity
What is acceleration?
A change in velocity
What is Newton’s first law of motion
If the resultant force acting on a stationary object is zero then the object will remain stationary.
If the resultant force acting on a moving is object zero, then the object will continue moving in the same direction at the same speed (with the same velocity)
What is Newton’s second law of motion?
The acceleration of an objectis proportional to the resultant force acting on the object and inversely proportional to ne mass of the object.
What is Newton’s third law of motion?
Whenever 2 objects interact the forces they exert on each other are equal and opposite
