UNIT 2 - NEWTON'S LAWS

Question 1

WHAT IS INERTIA ?

Answer 1

A resistance to a change in motion.
An object of a greater mass has a greater inertia
A greater resultant force is then required to change its motion

Question 2

WHAT IS THE DIFFERENCE BETWEEN WEIGHT AND MASS ?

Answer 2

Mass is the amount of matter in an object (kg)
Weight is a force, gravity acting upon a mass (N)

Question 3

WHAT IS THE FORMULA FOR WEIGHT ?

Answer 3

Weight (N) = Mass (kg) x Gravitational Field Strength ( N/Kg)

Question 4

WHAT IS GRAVITY ON EARTH ?

Answer 4

Approx 10N/Kg

Question 5

NEWTON’S FIRST LAW

Answer 5

An object will remain at rest or at a constant motion unless acted upon by an external resultant force

Question 6

NEWTON’S SECOND LAW

Answer 6

Resultant Force = Mass x Acceleration

F = M a

Acceleration is directly proportional to F
A is inversely proportional to M

Question 7

NEWTON’S THIRD LAW

Answer 7

Every action has an equal and opposite reaction

Question 8

WHAT IS TERMINAL ?

Answer 8

Terminal speed is the constant speed that an object reaches when moving through the air.
It occurs when air resistance is equal to weight, the resultant force is zero and no further acceleration occurs.

Question 9

HOW DOES TERMINAL SPEED RELATE TO SKYDIVING ?

Answer 9

Initially when the diver jumps Weight is greater than air resistance causing the sky diver to accelerate
As she accelerates air resistance increases
Continues until AR is equal to weight. This is Terminal velocity
When parachute is released air resistance increases due to increase surface area, slowing her down
As the skydiver slows, Forces balance and a new terminal velocity