Motion & forces Flashcards
What is a vector
Force with magnitude and direction
What is a scalar
Force with magnitude
examples of a vector
Velocity
Displacement
Acceleration
Force
examples of a scalar
speed
distance
time
what is the gradient on displacement time graph
Velocity
What is the gradient on a velocity time graph
acceleration
What does a straight line mean on a displacement graph
stationary
what does a straight line mean on a velocity time graph
constant speed
what is the typical wind speed
5 m/s
speed of sound
340 m/s
walking speed
1.4 m/s
running speed
3m/s
what is the value for acceleration due to gravity
10
What is Newton’s first law
an object has constant velocity unless acted upon it by a resultant force
what is Newton’s second law
force = mass x acceleration
what is circular motion
when an object is moving in a circle
* moves out at constant speed
* direction is changing constantly
* velocity is also changing
* accelerating
what is centripetal force
the full directed towards the center of the circle which allows for acceleration
what is Newton’s third Law
every action force has an equal and opposite reaction
what is inertia mass
how difficulty is to change the velocity of an object
how is a inertia mass measured
force / acceleration
What is the average human reaction time
0.25s
how do you conduct the ruler drop experiment
- drop ruler at random time
2.record the distance from the bottom of the ruler to the point where it was caught - measure reaction time
what is thinking distance
the time it takes for you to react to the situation
what is breaking distance
distance it takes for the car to completely stop
what effects thinking distance
- Speed
- Tiredness
- Distractions
what affects breaking distance
- Poor road conditions
- Worn break pads
- Mass of passagers
what is the average mass of a car
1500kg
who is work done to stop equal to
the initial kinetic energy of the vehicle
