Physics Flashcards
(35 cards)
What does a scalar quantity have and not have
Has Magnitude but does not have any specific direction
What does a vector quantity have and not have
Has both magnitude and a specific direction
What are some vector and scalar quantities
Displacement/distance
Acceleration
Velocity/speed
Force
Weight/mass
Momentum
Energy
What is velocity
Velocity is speed in a stated direction
What is the speed equation
Speed (m/s) = Distance (m) / time (s)
What is the distance traveled equation
Average speed (m/s) x Time (s)
How can speed be determined
By analysis of the gradient of distance/time graphs
what is used to determine the speed of objects in a laboratory
A range of methods such as light gates
What is the typical speed for walking
2.5-4 mph
What is the typical speed for wind
about 12 m/s
What is the typical speed for sound
331 m/s
what does Newtons first law of motion describe
The effect of balanced and unbalanced G-forces on an object in the following situations:
Where the resultant force on a body is zero i.e. the body is moving at a constant velocity or is at rest
Where the resultant force is not zero i.e. the speed and or direction of the body changes
What equation is weight defined by
Weight = mass (kg) X Gravitational field strength
What is weight
A force which is correctly measure in newtons
There is a relationship between the weight of a body and the gravitational field strength
True or False?
True
What is gravitational strength affected by
Distance
What do energy diagrams represent
Energy transfers
Can energy be created or destroyed
No
What are the different ways energy can be transferred in
An object can be projected upwards or up a slope
A moving object hitting an obstacle
An object being accelerated by a constant force
A vehicle slowing down
Where there are energy transfers in a closed system there is no what
Change to the total energy in that system
In all system changes energy is dissipated so that it is…
Stored in less useful ways
When do mechanical processes become wasteful
When they cause a rise in temperature so dissipating energy in heating the surroundings
What do waves transfer
energy and information without transferring matter
What is the efficiency equation
efficiency = useful energy transferred by the device / total energy supplied to the device
