Newtons Laws Flashcards
What is newtons 1st law?
If resultant force acting on object is 0, acceleration is 0
What is newtons 2nd law?
An object will accelerate if there is a resultant force acting on object.
The acceleration of an object is:
Proportional to resultant force
Inversely proportional to mass
What is newtons 3rd law?
When 2 objects interact, the forces exerted on each other are equal and opposite
What is inertia?
How difficult it is to change velocity
What is the formula for newtons 3rd law?
Force = mass x acceleration
What happens when you increase inertial mass?
It is more difficult to change its velocity
What is the independent, control and dependent variable for newtons practical?
Ind: resultant force or mass
Dep: acceleration
What is resultant force?
Overall force one a point or object
Describe the movement of an aircraft when resultant force is 0
Moving at constant speed
As an aircraft accelerates before take off, acceleration decreases even though force is constant. Why?
As speed increases so does air resistance
This reduces resultant force as air resistance will increase until the 2 forces are balanced
This means resultant force is 0
What is the steps for the acceleration practical?
Use ruler to measure 20cm intervals in chalk on the bench
Attach pulley at end of bench
Tie string to pulley
Pass string over pulley
Attach weight of 1N
hold trolley at starting point
Release trolley and use stopwatch
Repeat by decreasing the weight added
What are light gates used for?
To measure time taken
Why does a bowling ball decelerate as it travels along the lane?
There is air resistance
Resultant force is opposite direction to velocity
So work is done on ball
Why does a bowling ball slow down as it hits the pin?
Momentum conserved in collisions
Momentum of pin increases so momentum of ball decreases
Explain why a jet pack moves up when water is forced down
There is an equal and opposite force acting on jet pack
So resultant force is downwards
