Chapter 3- Motion Flashcards
(18 cards)
Define: Speed
Distance travelled per unit time
What does the gradient on a distance-time graph represent?
Speed
Define: Velocity
Displacement per unit time
What does the gradient on a displacement-time graph represent?
Velocity
If the gradient =0 on displacement-time or distance time graph what is the object doing?
Object is stationary
Define: Acceleration
Change in velocity per unit time
What does the gradient on a velocity-time graph represent?
Acceleration
What does gradient = 0 represent on a velocity-time graph
Object is either
A) travelling at constant velocity
B) acceleration = 0
What does the area under a velocity-time graph represent?
Total displacement of an object
Define: Stopping distance
The total distance travelled between when a driver can see a hazard and when the vehicle stops
Define: Thinking distance
Distance between seeing a hazard and applying the brakes
Define: Braking distance
Distance travelled from time breaks are applied to when car comes to halt (rest)
Equation for Thinking distance?
Thinking distance = speed x reaction time
Factors effecting thinking distance?
Tiredness, alcohol, drug use
Factors effecting breaking distance?
Icy road conditions, quality of car breaks, road quality
Value for g free fall in physics?
9.81
How do you determine free fall, g, using electromagnet and trap door experiment?
A) electromagnet hold ball above trap door
B) when current is switched off, a timer is triggered and ball falls instantaneously as electromagnet demagnetises
C) when ball hits the trap door timer stops
D) from measuring distance and the time form timer you can use
S= 1/2 at^2 (making a subject)
Why is horizontal velocity for a projectile constant
gcos(90) =0
Therefore horizontal velocity is not effected by a fall.
