Chapter 3: Motion Flashcards
What are distance time graphs used for
To represent motion of objects
How is a stationary object represented on a distance time graph
Horizontal straight line
How is an object moving at constant speed represented on a distance time graph?
Straight sloping line
Displacement vs distance
Displacement is a vector and distance is a vector
Acceleration def
Rate of change of velocity
Acceleration: vector or scalar
It is determined from velocity therefore it is a vector
Acceleration on velocity time graphs
Gradient
Straight line on velocity time graph means
Constant acceleration
Straight line of zero gradient on v/t graph means
No acceleration
Straight line of negative gradient on v/t graph means
Constant deceleration
Curve with changing gradient on v/t graph
This means the acceleration is changing
List the suvat equations
V = u + at
S = ut + 1/2at^2
S = (u+v/2)t
V^2=u^2+2as
Stopping distance definition
The total distance travelled from where the driver sees a reason to stop to when the vehicle stops
Thinking distance definition
The distance travelled between the moment when you first see a reason to stop to the moment when you use the break
Braking distance definition
The distance travelled from the time the brake is applied until the vehicle stops
Thinking distance equation
Thinking distance = speed x reaction time
Factors affecting stopping distance
Speed, The mass of the car how worn the brakes are, how warm the tires are, and the road surface
Factors affecting thinking distance
Fatigue, intoxication, distraction, visual impairment
What do all objects with mass do
They exert a gravitational force on each other
