03 Motion - 3rd Form Flashcards
In which part of the graph (A, B or C) is the object moving the fastest?
A
- gradient of the line is the steepest
- more distance covered per time
- faster speed
In which graph/s is the object travelling at a constant speed?
a) and e)
gradient is constant throughout
Describe what is happening in the graph and explain how you know.
The object is accelerating or speeding up from the starting position
The gradient of the line is increasing, therefore velocity is increasing.
Which sketch (red or green) represents a faster velocity?
Green- more steep line
Object is covering more distance per time
What is the SI unit for displacement or distance travelled?
metre or m
In which part of the graph (A, B or C) is the object travelling back to the start.
C
-gradient of the line is negative
velocity is negative
-travelling in opposite direction to part A
What is the equation for average speed?
average speed = total distance travelled/ time taken
What feature of a velocity-time graph gives the acceleration?
gradient of velocity-time graph
What feature of a velocity-time graph gives the distance travelled?
area under a velocity-time graph
In which graph/s is the object decelerating?
d)
gradient is getting less steep
A horizontal line on a velocity-time graph shows?
constant velocity, no acceleration
A horizontal line on a distance-time graph shows what?
That the object is not moving, has zero speed
If an object accelerates at 10 m/s2. How fast would it be travelling after 10 s if it started at rest?
It will gain 10 metres per second every second.
After 10 s if should be travelling at 100 m/s!
What feature of a distance-time graph gives the velocity?
gradient of distance-time graph
Which ticker tape shows an object which is decelerating?
ticker tape Z
- dots get closer together
- object is covering less distance per unit time
- object is slowing down
In which part of the graph (A, B or C) is the object stopped?
B
Gradient is zero therfore speed is zero- obejct is not moving
What is the SI unit for acceleration?
metre per second squared or m/s2
Describe what is happening to the velocity in this distance time graph.
A –> B velocity is constant
B –> C velocity is zero
C –> D velocity is increasing
D –> E velocity is zero
E–> F velocity is constant but opposite direction
define acceleration
Acceleration is the rate of change of speed
OR
The change in speed per unit time
In which graph/s is the object travelling at a constant speed?
a) and e)
gradient is constant throughout
How would you sketch a d-t graph of an object accelerating away from a point
The gradient of the line is increasing
speed is increasing
object is accelerating
What is the SI unit for time?
seconds or s
What does this ticker tape show about the movement of the object?
- dots are evenly spaced
- object is covering the same distance per unit time
- object is travelling at a constant speed, it is not accelerating
What is the SI unit for velocity or speed?
metre per second or m/s
In which graph/s is the object decelerating?
d)
gradient is getting less steep
How do you find the instantaneous speed from a distance time graph?
Calculate the gradient of the line at that instant.
Draw a triangle and calculate
speed = rise/ run - distance travelled/ time
What feature of a distance-time graph gives the velocity?
gradient of distance-time graph
speed =distance / time
rearrange for distance or d
distance = speed x time
What does this ticker tape show about the movement of the object?
- dots are moving further apart
- object is cover more distance per unit time
- object is speeding up, accelerating
Sketch a d-t graph of an object stationary at 3 metres.
What does this ticker tape show about the movement of the object?
- dots are evenly spaced
- object is covering the same distance per unit time
- object is travelling at a constant speed, it is not accelerating
Which ticker tape shows an object which is decelerating then accelerating?
ticker tape E
- dots get closer together, then further apart
- object is covering less distance per unit time, then more distance per unit time.
- object is slowing down then speeding up, decelerating, then accelerating
In which graph/s is the object at rest?
b)
gradient is zero
What does this ticker tape show about the movement of the object?
- dots are moving further apart
- object is cover more distance per unit time
- object is speeding up, accelerating
In which part of the graph (A, B or C) is the object stopped?
B
Gradient is zero therfore speed is zero- obejct is not moving
What is the unit for acceleration?
m/s2
Which ticker tape shows an object which is decelerating then accelerating?
ticker tape E
- dots get closer together, then further apart
- object is covering less distance per unit time, then more distance per unit time.
- object is slowing down then speeding up, decelerating, then accelerating
speed = distance /time
rearrange for time or t
time = distance / speed
What is the equation for acceleration?
a = (v-u)/t
OR
a = change in velocity / time
If an object is decelerating at 2 m/s2, how fast is it going after 4 seconds if it was travelling at 14 m/s?
It will lose 2 metres per second every second.
after 4 seconds it will decrease its velocity by 8 m/s
14 - 8 = 6 m/s
Which of the following represents distance travelled on a velocity-time graph?
A. the area under the graph
B. The gradient of the graph
C. The highest point on the graph
A. the area under the graph
