Section 3: Physics

Question 1

What are the principles of the atomic theory?

Answer 1

Atoms experience short-range attraction: form molecules
When atoms or molecules are far apart, they barely interact: explains liquids and gases
When atoms or molecules come very close to one another, they powerfully repel: ordinary matter is not very dense, lot of space between atoms
Atoms and molecules are in never ending motion: diffusion

Question 2

What is a force?

Answer 2

Agent of change

Question 3

What is the difference between mass and weight?

Answer 3

Mass: how much matter there is in a material object. Fixed property, constant everywhere in universe. Masses interact gravitationally which causes weight

Weight: downward force exerted by an object at the surface of Earth. Varies by location

Question 4

What is speed?

Answer 4

Vav=l/t
Average speed = length travelled / time travelled
Always positive

Question 5

If a person drives at 25.3 km/hr for 4.72 hours to get to a destination. How far have they travelled?

Answer 5

Approximately 119 km
119.416 km
Vav x t = l