SP1: Motion Flashcards
Define scalar
Quantities that only have magnitude
Define vector
Quantities that have both magnitude and direction
Give three examples of a scalar quantities
- distance
- temperature
- mass
- speed
- energy
- density
Give three examples of vector quantities
- displacement
- force
- gravity
- weight
- velocity
- acceleration
- momentum
How is the direction of a vector given?
Drawn as an arrow or given in a written description
What does the length of the arrow suggest?
The magnitude of the quanitity
What is the equation for speed?
distance/time
What is the equation for velocity?
displacement/time
Define speed
The rate of change of distance
What is the unit for speed?
m/s
What is the typical speed for someone who is walking?
1.5 m/s
What is the typical speed for someone who is running?
3 m/s
What is the typical speed for someone who is cycling?
6 m/s
What is the typical speed for someone who is driving?
13-30 m/s
What is the typical speed for a train?
50 m/s
What is the typical speed for a plane?
250 m/s
What are the two measurements needed to calculate speed?
- the distance the object has travelled
- the time the object took to travel that far
What does a horizontal gradient on the distance-time graph show?
The object is stationary
What does a sloping gradient on the distance-time graph show?
The object is moving
How do we calculate the speed from a distance-time graph?
From the gradient of the line
What does a steep gradient on a distance-time graph represent?
The object is moving fast
What is on the x-axis of a distance-time graph?
Time
What is on the y-axis of a distance-time graph?
Distance
Define acceleration
The rate of change of velocity
What are the units for velocity?
m/s
What is the equation for velocity?
displacement/ time
What does a negative gradient on a distance-time graph show?
The object is moving at a constant speed, but it is going back to its starting point
What is the equation for acceleration?
(change in velocity)/time
When do we know that an object is accelerating?
- when it changes velocity
- when it changes its distance
What is deceleration?
Negative acceleration: when an object is slowing down/ moving in the opposite direction
What are the units for acceleration?
m/s^2
What is the typical acceleration for running?
2 m/s^2
What is the typical acceleration for a family car?
1 - 7 m/s^2
What is the typical acceleration for a motorbike?
1 - 10 m/s^2
What is the typical acceleration for a rollercoaster?
30-60 m/s^2
What is the acceleration in freefall due to Earth’s gravity?
9.8 m/s^2 if no other forces, such as air resistance are acting upon the object
What does a horizontal line represent on a velocity-time graph?
A constant velocity
What does the gradient represent in a velocity-time graph?
Acceleration
What does a downwards sloping line represent on a velocity-time graph?
Deceleration
What does a line below the horizontal axis represent on a velocity-time graph?
The object is travelling in the opposite direction
What does the area under a velocity-time graph represent?
The distance the object has travelled
What is on the x-axis of the velocity-time graph?
Time
What is on the y-axis of the velocity-time graph?
Velocity
What equation represents the object in uniform acceleration?
(final velocity)^2 – (initial velocity)^2 = 2 × acceleration × distance
Why is it that when an object travels in a circle, the velocity is constantly changing despite the constant speed?
The direction of the object keeps changing
What must act on an object to cause acceleration?
A resultant force
What resultant force acts in a circular motion which causes the object to accelerate?
centripetal force
