Topic 5, Part 2 - Forces ye dawg Flashcards
what are scalar quantities
they are quantities that only have magnitude and no direction
how are vectors usually represented
by an arrow and the length of the arrow shows the magnitude and the direction of the arrow shows the direction of the quantity
what is a distance
distance is just how far an object has moved. it is a scalar quantity.
what is a displacement
displacement is a vector quantity. it measures the distance and direction in a straight line from starting point to endpoint
example of distance and displacement
walk 5 meters north, walk 5 meters south. your displacement is 0m and your distance traveled is 10m
what are speed and velocity
speed is just how fast you are going with no regard to the direction e.g. 30mph. velocity is speed in a given direction e.g. 30mph north
examples of speed and velocity
a car can have a constant speed but a changing velocity such as going around a roundabout.
speed equation
speed (M/S)= distance( m) / time (S)
typical everyday speeds of a person
walking 1.5 m/s
running 3m/s
cycling 6m/s
typical everyday speeds of vehicles
car 25m/s
train 30m/s
plane 250m/s
what is acceleration
acceleration is the change in velocity in a certain amount of time
acceleration equation
Acceleration (m/s²) = Change in velocity (m/s) / Time (s)
how does friction slow things down
friction always acts in the opposite direction of movement.
What is drag
drag is a resistance you get in a fluid (gas or liquid). air resistance is a drag. as drag increases so does speed
what is terminal velocity
terminal velocity is when an object is falling and it has reached its max speed due to air resistance and weight
what affects terminal velocity
less streamlined objects have a lower termianal velocity. larger surface area, lower terminal velocity.
what is newtons first law
if the resultant force of an object is stationary, the object is zero and will remain stationary. if the resultant force on a moving object is zero, it’ll carry on moving at the same velocity.
What is newtons second law
acceleration of an object is directly related to the net force and inversely related to its mass
equation for resultant force
Resultant force (n) = Mass (Kg) X Accerlation (m/s²)
what is inertia
inertia is the tendency for a motion to remain unchanged
what is newtons third law
when two objects interact, the force they exert on each other are equal and opposite
