Physics Flashcards
What does a scalar quantity have?
A scalar quantity has magnitude but no specific direction.
What does a vector quantity have?
A vector quantity has both magnitude and specific direction.
What is the difference between a scalar and a vector quantity?
A vector quantity has both magnitude and specific direction but a scalar quantity had just magnitude.
What do scalar quantities include?
Density, Time, Energy, Resistance, Speed, Volume, Mass, Power
What do vector quantities include?
Velocity, Force, Acceleration, Weight, Momentum
What is Distance?
Distance is a scalar quantity that referes to how much ground an object has covered during its motion
What is Displacement?
Displacement is a vector quantity that refers to how far out of place an object is from it’s starting position, it is the objects overall change in position.
What is velocity?
Velocity is speed in a stated direction
How do you work out speed?
Speed = distance/time
How do you work out the distance travelled?
distance travelled = average speed x time
How can speed be determined?
Speed can be determined by analysis of the gradient of distance/time graphs
True or False? There are typical speeds encountered in everyday experience for wind and sound, and for walking, running, cycling and other transportation systems?
True
How is weight defined?
weight = mass x gravitational field strength (W = M x G)
True or False? Weight is a force?
True and it is correctly measured in newtons.
How is weight measured?
In Newtons
What is gravitational field strength affected by?
Distance
What is there a relationship between?
The weight of a body and the gravitational field strength acting upon it.
Why is acceleration proportional to Force and Mass?
As we increase the force on an object the acceleration increases proportionally. The mass does not change as the acceleration increases.
What is Newtons first law of motion?
An object at a constant velocity will remain at the same velocity unless acted on by a resultant force
True or false? In all system changes energy is dissipated so that it is stored in less useful ways
True
How can unwanted energy transfers be limited?
Unwanted energy transfers can be limited by methods including through lubrication, thermal insulation
What is the equation to work out efficiency?
Efficiency = (useful energy output) / (total energy input)
How can efficiency be increased?
Efficiency can be increased by minimising unwanted energy transfers