Topic 10 - Newton's Laws Flashcards
What is mass?
The amount of matter an object contains, constant.
What is inertia?
A measure of how difficult it is to change the object’s motion.
What is the relationship between inertia and mass?
An object with a high mass has more inertia than an object with a lower mass.
What is weight?
The force that acts on the object when it is in a gravitational field.
What is weight measured in?
Newtons (N)
What is the equation for weight?
Mass x Gravitational field strength
What is mass measured in?
Kilograms (kg)
What is gravitational field strength measured in?
Newtons per kilogram (N/kg)
What is Newton’s first law?
An object will remain in the same state of motion unless acted upon by a resultant force.
What happens if an object is stationary and no resultant force is acting on it?
It remains stationary
What happens if an object is moving and no resultant force is acting on it?
It remains moving at the same speed
What is a resultant force?
The sum of all of the forces acting on an object.
What is Newton’s second law?
A force may cause a mass to accelerate (change speed or direction or both).
What is the equation for Resultant force?
Mass x Acceleration
What is Newton’s third law?
For every action, there is an equal and opposite reaction.
What is the only acting force in free fall?
Object’s weight, acting downwards due to gravity
What is acceleration due to gravity?
The constant rate at which an object accelerates in free fall.
What is the acceleration on Earth?
9.81 m/s2 (10)
What is air resistance?
A frictional force that opposes the motion of objects moving quickly through air.
What does air resistance do to a falling object?
Slows it down, the force due to air resistance increases as the speed of a falling object increases.
What is terminal velocity?
The fastest that an object can fall.
Terminal Velocity 1
At the start of the motion, the speed increases as the object is accelerating due to gravity.
Terminal Velocity 2
This increase in speed causes an increase in air resistance.
Terminal Velocity 3
The acceleration then starts to decrease as air resistance opposes the motion.
Terminal Velocity 4
The air resistance increases until it equals the weight of the object.
Terminal Velocity 5
Once the weight and force due to air resistance are equal, the object stops accelerating and has reached terminal velocity.
