Motion Flashcards
What is distance!?
It is how far an object moves. It is the numerical description for how far apart two things are
Is distance vector or scalar!?and why!?
It is scalar as it does not include an associated direction
What is speed!?
Speed is the distance travelled in a know period. It is the rate of change of distance
What is rate of change!?
The amount of change in size of a quantity each second
What is the typical speed of walking!?
1.5m/s
What is the typical speed for running!?
3m/s
What is the typical speed for cycling!?
6m/s
What is the typical speed for a car!?
13-30m/s
What is the typical speed of a train!?
50m/s
What is the typical speed for a aeroplane!?
250m/s
Is speed scalar or vector!?
Scalar
How do you calculate speed!?
Speed= distance/ time taken
What is velocity!?
The speed of an object in a given direction
How do you calculate velocity!?
Velocity= displacement/ time
Is velocity scalar or vector!?
Vector: uses a magnitude and always uses a direction
What type of graph is distance travelled represented by!?
A distance- time graph
What does a horizontal line on a distance-time graph show!?
The object is stationary
How is speed calculated on a D-T graph!?
It is calculated from the gradient of the D-T graph
What is a gradient!.
Another word for steepness. On a graph, the gradient is defined as being the change in the ‘y’ value divided by the change in the ‘x’ value. It defines how steep a line is.
What is acceleration!?
Acceleration is the rate of change of velocity. It is the amount that velocity changes per unit time
How is acceleration measured!?
Acceleration = change of velocity ÷ time taken.
What is uniform acceleration!?
When a moving object’s speed changes the same amount per second
What is the acceleration of any free falling object near earth’s surface!?
9.8m/s squared
What is constant velocity also known as!?
Terminal velocity
What is the equation for uniform acceleration!?
Final velocity (squared) - initial velocity (squared) = 2 x acceleration x distance
What is the typical acceleration for running!?
2m/s squared
What is the typical acceleration for a family car!?
1-7m/s
What is the typical acceleration for a motorbike!?
1-10m/s squared
What is the typical acceleration for a rollercoaster!?
30-60m/s squared
What type of graph is the velocity of a moving object written on!?
A velocity-time graph
What does the horizontal line of a V-T graph show!?
It shows that the object is at a constant velocity
What does a sloping line on a V-T graph show!?
Shows that the object is accelerating
What is the gradient equal to on a V-T graph!?
Acceleration
How can you Calculate the distance travelled on a V-T graph!?
The distance travelled by an object can be calculated from the area under a velocity-time graph.
The area under the graph can be calculated by:
using geometry (if the lines are straight)
counting the squares beneath the line (particularly if the lines are curved).
What happens to an object moving at a constant speed in a circle!?
It’s direction constantly changes. This is causes a change in velocity because it’s a vector
A change in velocity results in acceleration, so an object moving in a circle is accelerating even though its speed may be constant.
An object will only move if……
A resultant force acts on it
What is a resultant force!
The single force that could replace all the forces acting on an object, found by adding these together. If all the forces are balanced, the resultant force is zero.
Gravitational attraction provides what for the earth!?
the centripetal force needed to keep a planet in orbit around the Sun, and a satellite in orbit around a planet.
Question: gravitational attraction between the Earth and the Moon keeps the Moon in orbit around the Earth. An object moving in a circular orbit at a constant speed has a changing velocity. Why!?
This is because velocity is a vector quantity that depends on speed and direction. The object in orbit is accelerating, even though its speed remains constant, because its velocity is changing.
What is air resistance!?
A force of friction produced when an object moves through the air.
What is thrust!?
A force used to move a body forwards or up
What is terminal velocity!?
The maximum speed of an object, reached when the forces moving the object are balanced by its frictional forces.
