2. Kinematics Flashcards
What is the difference between average and instantaneous speed?
Average speed is a measure of the speed of the object over the whole journey. Instantaneous speed is the speed at one particular point.
What is the symbol for average speed?
v̅
What is the unit for average speed?
ms-1
What is the symbol for distance?
d
What is the unit for distance?
m
What is the symbol for time?
t
What is the unit for time?
s
What is the symbol for instantaneous speed?
v
What is the unit for instantaneous speed?
ms-1
Describe how you could measure the average speed of an object.
Measure the distance travelled using a metre stick and the time using a stopwatch, then calculate v̅ from d = v̅t
Describe how you could measure the instantaneous speed of an object.
Measure the width of the object using a ruler and the time to pass through the light gate using an electronic timer, then calculate v from d = vt
Which equation do you write as the first line of working when interested in calculating average speed?
d = v̅t
Which equation do you write as the first line of working when interested in calculating instantaneous speed?
d = vt
In the equation for acceleration, what is a?
Acceleration
In the equation for acceleration, what is v?
The final speed
In the equation for acceleration, what is u?
The initial speed
Describe how you could measure the acceleration of an object.
Two light gates will measure the instantaneous speed using the mask length (measured by ruler) and time to pass the light beam (measured by electronic timer). An electronic timer measures the time taken to travel between the two light gates. We then put these values into a = (v-u)/t
What are the units for a?
ms-2
What is speed?
Speed is how much the distance travelled changes every second
What is acceleration?
Acceleration is how much the speed of the object changes every second
How could you find how far the object had travelled just from the graph?
distance travelled = area under the graph
