Topic 9 - Motion Flashcards
What is acceleration?
The change of velocity per second.
What is acceleration measured in?
Metres per second squared (m/s2).
What is displacement?
A distance in a given direction.
What is displacement measured in?
Metres/Kilometres in a cardinal direction.
What is gradient?
Change in the quantity plotted on the x-axis divided by the change in the quantity on the y axis. If the x axis is seconds elapsed and the y axis is metres travelled, gradient will be measured in metres per second.
What is tangent?
A straight line drawn on a point on a curved line so that it has the same gradient as the curve at that point.
What is velocity?
Speed in a given direction. This is measured in m/s.
What is the equation relating speed, distance and time?
Speed (m/s) = distance (m) / time (s)
What is a distance-time graph?
A graph comparing distance over time.
What is average speed?
Total distance / time
What is instantaneous speed?
Speed at a given position.
What can be said about an object moving at a constant speed but turning?
The object is accelerating.
What is deceleration?
An decrease in velocity over time.
What is the equation linking initial and end velocity, acceleration and displacement?
Final velocity squared = initial velocity squared + 2x ( acceleration x displacement). V2 = U2 + 2as
How do you calculate gradient?
Change in Y / Change in X
What is speed?
Distance (metres) / time (seconds)
What do long-distance vehicles have to record distance?
Tachographs
What is true about an object moving in a circle?
It has a direction of motion that changes continuously as it goes around. Its velocity is not constant even if speed is constant.
What is acceleration defined as?
The change of veloctiy per second.
What is the equation for acceleration?
acceleration = change in velocity / time taken for the change to occur.
What is the equation for initial/final velocity?
V2 - U2 = 2as
Final velocity squared - initial velocity squared = 2 x acceleration x displacement
How do you find acceleration on a velocity-time graph?
Acceleration = gradient
What does braking do?
Reduces the velocity of a vehicle.
What is braking on a velocity-time graph?
When velocity decreases braking is occuring.
What two units could be used for speed/velocity?
Km/h
What do you do to find gradient in a curved graph?
Draw a tangent at the point you are investigating.
How do you find distance travelled on a velocity-time graph?
The area under a line of velocity-time graph represents distance travelled.
