Topic 2: Motion And Forces Flashcards
What is Newton’s first law?
An object has a constant velocity unless a resultant force acts on it
What is a real life example of newtons first law?
Two marbles colliding
- if resultant force acts on object it accelerates
- acceleration is velocity/time
- so velocity will change
- so speed/direction of object will change
What is Newton’s second law?
force = mass x acceleration
where force is Newtons
mass is kilograms
and acceleration is ms-2
How can constant and average speed be measured?
distance/time
How do light gates measure speed?
Set up two light gates at either end and measure distance between them, as soon as object passes through it will measure time it takes to reach second light gate
What is Newton’s third law?
Every action has an opposite and equal reaction
What is an example of Newton’s third law?
two marbles colliding: force exerted by one is the same as the other
What is a vector?
Has a magnitude and direction
What is a scalar?
Has a magnitude
3 examples of a vector?
velocity, momentum, acceleration
3 examples of a scalar
time, distance, speed
What is circular motion?
An object moving in a circle with a constant speed
What happens in circular motion?
The speed is constant but the direction is constantly changing
So velocity is always changing
so it’s accelerating
What is momentum?
Mass in motion - momentum is always conserved in a collision due to no external forces
What happens to momentum in collisions?
The total momentum before = total momentum after because momentum remains constant
