Week 5

Question 0

Law of inertia

Answer 0

An object at rest tends to stay at rest and an object in motion tends to stay in motion unless acted apron by an unbalanced force.

Question 1

Explain Newtons contributions.

Answer 1

Calculus 
Light is composed of rainbow colours
Reflective telescope
Laws of motion 
Theory of gravitation

Question 2

Equal forces in opposite directions produce what in inertia?

Answer 2

No motion.

Question 3

Unbalanced forces and describe

Answer 3

Refer to truck diagram.

Question 4

If objects in motion tend to stay in motion, why don’t they keep moving forever.

Answer 4

There’s almost always an unbalanced force upon them

Question 5

Give two examples of unbalanced forces.

Answer 5

Friction and gravity

Question 6

Mass is the measure of what?

Answer 6

Amount of matter in an object measured in kgs.

Question 7

Define inertia?

Answer 7

A property of an object that describes how much it will resist change to the motion of the object.
More mass = more inertia.

Question 8

4 main types of friction?

Answer 8

Sliding eg ice skating
Rolling eg bowling
Fluid friction (air or liquid) eg air or water resistance
Static eg initial friction when moving an object

Question 9

Newton’s second law (equation for force)?

Answer 9

Force = mass x acceleration (f = ma)

Question 10

Acceleration of gravity on earth?

Answer 10

9.8 mL^2 weight (force) = mass x gravity (earth)

Question 11

Moons gravity?

Answer 11

1/6th of earth’s weight

420 newtons on earth = 70 newtons on moon

Question 12

Weight is a measure of?

Answer 12

Force of gravity on the mass of an object. Measured in newtons.

Question 13

Newton’s third law

Answer 13

For every action there is an equal and opposite reaction.

Question 14

Eg of Newton’s third law

Answer 14

Stand on slippery floor, push against wall = slide in opposite direction. Pushed on wall but wall pushed back with equal and opposite force.

Question 15

Equation for mass?

Answer 15

m=f÷a