Physics Module 3 Flashcards
What does an unbalanced force mean on a car?
Acceleration in the second direction of the force- newtons 2nd law of motion
What does a balanced force mean?
Balanced forces so steady speed and direction
What is acceleration?
How quickly you speed up
On a speed time graph what does the flat bit mean?
Steady speed
On a speed time graph what is the area underneath?
Distance traveled at the time interval
What does velocity describe?
Speed and direction
What is speed?
Distance travelled in a certain time
What do the curves show on a distance time graph?
Acceleration/ deceleration
What are the 3 ways friction occurs?
Friction between solid surfaces which are gripping, friction between solid surfaces which are sliding past each other, resistance/drag from fluids
What does the resistance force equal?
Accelerating force
What does terminal speed depend on?
Drag, the greater the drag the lower the terminal speed
What are the 5 different force diagrams and what forces do they show?
Stationary object-balanced Steady horizontal speed-balanced Steady vertical speed- balanced Horizontal acceleration-unbalanced Vertical acceleration-unbalanced
What is gravity?
The force of attraction between all masses
What happens to mass and weight of an object on the moon?
Same mass but different weight
Which direction do gravity and weight act?
Downwards
What do thrust/push/pull do?
Speed something up
What do drag/air resistance/friction do?
Slows something down
As speed doubles on a graph what happens to the braking distance?
It increases 4 fold
What happens to the braking distance as speed trebles on a graph?
Braking distance increases 9 fold
What affects thinking distance?
Speed/concentration
What affects braking distance?
Speed/weight/brake condition/grip condition (road surface/weather/tyre condition)
How do crumple zones work?
They increase time and change shape to absorb kinetic energy from the car and reduce the impact on passengers
How do ABS brakes work?
They help drivers keep control of car steering when braking hard, ABS pump on and off to stop wheels locking and prevent skidding
What can cause a change in momentum?
A change in velocity
The longer it takes for a change in momentum means…
The smaller the force, reduces injuries
