GRADE 8 PHYSICS EXAM REVIEW

THEME: PHYSICS REVIEW
The exam will be a mix of vocabulary matches, thinking questions, and understanding challenges.

FLUIDS (50%): Please understand the following concepts/ terms:

Archimedes' principle is: "A body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid."
Density= mass over volume = g/mL
Define a Fluid
Buoyant force/ Buoyancy
Friction
Flow
Containers
Volume
Mass
Weight
States of matter/ Particle Theory
Viscosity
Hydraulic system
Pneumatic system


MECHANICAL EFFICIENCY (50%)

MECHANICAL EFFICIENCY is the effectiveness of a machine and is defined as mechanical advantage over velocity ratio. To show the effectiveness of a machine one must compare its work input to its work output.

PASCAL'S LAW states that if you apply pressure to fluids that are confined (or can't flow to anywhere), the fluids will then transmit (or send out) that same pressure in all directions at the same rate.

WHAT IS ERGONOMICS? Ergonomics is the study of how your body interacts with your environment when you perform a task or activity. Know examples.

CLASSIFICATION OF LEVERS (Know examples of each)
• Class 1 - The fulcrum lies between the effort and the load
• Class 2 - The fulcrum is at one end, the effort at the other end and the load lies between the effort and the fulcrum
• Class 3 - The fulcrum is at one end, the load at the other end and the effort lies between the load and the fulcrum

Gears are wheels with teeth around their edges. The teeth fit together so that when one gear turns, its teeth push against another gear’s teeth, causing it to turn as well. Gears that are next to each other rotate in opposite directions. When a smaller gear drives a larger gear, the larger gear turns with more force. This is force magnification. When a larger gear drives a smaller gear, the smaller gear completes its turns faster. The gears are magnifying a movement.
Mr. L.