⭐️topic SP1 - Motion Flashcards
What does the speed of an object tell you?
How quickly it travels a certain distance
What are the units for speed?
Meters per second - m/s
What is the formula for speed?
Speed (m/s)= distance (m) / time (s)
How can you measure the speed of a fast object accurately in the lab?
By using light gates rather than a stopwatch
What is the typical walking speed?
1.4 m/s
What is the typical motorway speed limit?
31 m/s
What does a horizontal line on a distance time graph mean?
The object is stationary
What does a sloping straight line on a distance time graph mean?
The object is travelling at a constant speed
How do you calculate speed on a distance time graph?
By calculating the gradient of the line
What is acceleration?
A measure of how fast velocity is changing
What is a vector?
A quantity with a size and direction
What is a scalar?
A quantity with just a size
Give examples of a vector
Velocity, weight, displacement, acceleration and momentum
Give examples of a scalar
Distance, speed, energy, mass
What is displacement?
Distance covered in a straight line and has a direction
Why is displacement usually less than distance travelled?
As there are no bends or turns in the journey
What is velocity?
The speed in a particular direction
When is an objecting accelerating?
If it’s changing velocity or direction
What are units of acceleration?
Meters per second squared - m/s^2
What does an acceleration of 10m/s^2 mean?
Each second, the velocity increases by 10 m/s
What is the formula for acceleration?
a = (v - u )/ t
Where v is final velocity u is initial velocity and t is the time taken for the velocity to change
What does it mean if an acceleration has a negative value?
Then it’s a deceleration and the object is getting slower
How can acceleration be related to initial velocity, final velocity and distance travelled?
v^2 - u^2 = 2ax where x is the distance
What is the acceleration due to gravity?
9.8 m/s^2 but is often rounded to 10 m/s^2 in calculations and is represented by symbol g
What can a velocity time graph show?
The changing velocity of an object
On a velocity time graph:
What does a horizontal line mean?
Object is travelling at a constant velocity
On a velocity time graph:
What does a sloping line mean?
The object is accelerating
On a velocity time graph:
What does it mean if the line is sloping to the right?
The object is decelerating
On a velocity time graph:
How do you find the acceleration of an object?
From the gradient of the line
On a velocity time graph:
What does a negative velocity (below the x axis) mean?
The object is moving in the opposite direction
On a velocity time graph:
How do you know the distance travelled by an object?
By calculating the area under the velocity time graph
