Topic 2 - Motion And Forces Flashcards
What is a scalar quantity?
A quantity that only has magnitude but no direction.
What is a vector quantity?
A quantity that has both a magnitude and an associated direction
Three examples of vector quantities
Velocity
Displacement
Force
Give examples of scalar quantities
Temperature Mass Time Speed Distance Energy
What is velocity
The speed of an object in a specific direction.
Equation relating average speed, distance and time
Average speed = distance / time
On distance/time graph, what value does the gradient of the line represent?
The speed
On a displacement/time graph, what value does the gradient of the line represent?
The velocity
What must be done to calculate speed at a given time from a distance-time graph for an accelerating object?
Draw a tangent to the curve at the required time
Calculate the gradient of the tangent
Equation for the average acceleration of an object
Acceleration = (change in velocity)/(Time taken)
A = (v-u)/t
Equation final velocity with initial velocity, distance and acceleration
V^2 - U^2 = 2 x a x x
How can the distance travelled by object be calculated from a velocity-time graph?
It is equal to the area under the graph
On a velocity/time graph what does the gradient of the graph represent?
The acceleration
Typical value of the speed of sound
330m/s
Typical value for human walking speed
1.5m/s