Forces Flashcards
A value with magnitude only is a ________?
scalar
A value with magnitude and direction is a ____________?
vector
Distance an speed are examples of _________ quantities
scalar
Force, displacement and velocity are examples of __________ quantities
vector
What is a contact force?
A force between two object which are touching
What ia a non-contact force?
A force between objects which are separated by space.
Give two examples of contact forces
e.g. friction, air resistance
List three non-contact forces
gravitational, electrostatic, magnetic
Define weight
The force of gravity acting on an object’s mass
What device is used to measure weight?
A newtonmeter
What is the name of the single point at which an object’s mass appears to act?
centre of mass
The center of mas of an object is…
the single point at which the objects weight appears to act.
The single force which has the same effect as the combination of all the different forces acting on an object is the ______________ _______________.
resultant force
Work is done when an object is ….
… moved through a distance
Moving objects with mass are said to have __________?
momentum
State the law of conservation of momentum
In a closed system the total momentum before an event is equal to the total momentum after an event.
State the equation which links gravitaional field strength, mass and weight
W=mg
State the equation which links distance, force and work done
W=Fs
State the equation which links extension, force and spring constant
F=ke
State the equation which links distance, speed and time
s=vt
State the equation which links acceleration, change in velocity and time taken
a=Δv/t
State the equation which links acceleration, mass and resultant force
F = ma
State the equation which links mass, momentum and velocity
ρ = mv
What is the unit of weight?
Newtons (N)
What is the unit of mass?
kilograms (kg)
What is unit of gravitational field strength?
newtons per kilogram (N/kg)
What is the unit of work done?
Joules (J)
What is the unit of force?
Newtons (N)
What is the unit of distance?
meters (m)