8: Motion Flashcards
What is the difference between a scalar and a vector?
A scalar has no direction - it’s just an amount of something
A vector has a magnitude and a direction
How do you find the resultant vector?
Adding two or more vectors together
Define speed
How fast something is moving, regardless of direction
Define displacement
How far an object’s travelled from its starting point in a given direction
Define velocity
The rate of change of an object’s displacement (its speed in a given direction)
What is instantaneous speed?
The speed of an object at any given moment in time
What is the average speed?
Total distance covered, over the total time elapsed
What is another way of saying uniform acceleration?
Constant
Define free fall
The motion of an object undergoing an acceleration of ‘g’. Only gravity
What is/are the force(s) acting on an object in free fall?
Weight
Describe the rate of free fall for different objects
All objects free fall at the same rate
What is the main uncertainty in the experiments (light gates and trapdoor) to find the value g?
The height h
What is parallax, in the context of uncertainties?
Systematic error due to looking at the ruler at an angle
In a graph of displacement against time, how can you tell that something is accelerating?
Graph is curved
What does the graph (displacement against time), look like if the object is accelerating at a uniform rate?
Rate of change of the gradient will be constant
In a displacement time graph:
If there are two objects, both accelerating, how can you tell which is accelerating more?
Steeper curve
In a displacement time graph:
If there are two objects, both accelerating, how can you tell which is accelerating less?
Shallower curve