Motion And Forces Flashcards
What is the equation for average speed?
Initial speed+final speed/2
Or
Total distance/Total time
What is the equation for “rate or change of speed”
(Acceleration or retardation)
Final speed - Inital speed/Total Time
How to find max speed
AVG speed x2
Equation for velocity
Velocity=displacement/Time
Equations for average velocity
Total displacement/Total time
Or
Final velocity+initial Velocity/2
Equation for acceleration/retardation (velocity)
Final Velocity-initial velocity/2
What are the units for acceleration/retardation
M/s/s
Or
m/s^2 (squared)
What goes on the y and x axis of a displacement time graph
Displacement on Y axis
Time on x axis
Gradient = the velocity
Equation for weight
W=Mass *Gravity
What is weight class as
The gravitational force acting on a mass
What’s a scalar
Value without a direction
What’s a vector
Value with a direction
What is hooks law
The extension of a spring is directly proportional to the forces applied until the limit of proportionality
What’s the equation to calculate hooks law
F=kE
Force= Konstant * Extension
What goes on the x and y axis of a hooks law graph
Force on y
Extension on x
Gradient=k
What is pressure defined as
Force exerted per unit of area
Pressure equation
Pressure(N/cm^2 or N/m^2)=Force(N)/area(cm^2 or m^2)
What is a moment
Measurement of the turning effect (when a force makes something spin) of a force
What are the equations of a moment
f1d1=f2d2
Or
M= Force *distance to pivot
What is the Centre of Gravity
Point through which the whole object can act upon
What’s the equilibrium
State at which all forces are equal and object is balanced
What’s the Law of Moments
For an object to be in equilibrium/balance the sum of the clockwise and the anti-clockwise moments must be equal about the same point
What’s a way of showing the law of moments
CWM=ACWM
force x distance to pivot= force x distance to pivot
What’s Newton’s first law
An object will continue at a constant speed or remain stationary if all forces are balanced (resulutant forces=0)
What’s newtons 2nd law
Acceleration of an object is directly proportional to the resultant force and inversely proportional to the mass (1N will accelerate a mass of 1kg at a rate of 1m/s^2)
What is the equation to calculate Newton’s second law
Forces = Mass*Acceleration
What’s the definition of density
Amount of matter/mass in the unit of volume of a substance
What’s density’s equation and units
Density(g/cm^3 or kg/cm^3) = mass(g or kg)/volume(cm^3 or m^3)
Forces acting upon a fall
Weight pulling down to earth
Air resistance pulling up
(Resultant force will always be in favour of weight)
Why does a parachute slow down a falling person
Drag force inc with the speed of the fall-drag forces becomes greatest force there for slowing down fall
