Physical science exam 2


Question: Latent heat
Answer: The amount of heat needed to change the state of a substance


Answer: Another way of transferring energy that is caused by a vibration or a disturbance

Question: The Doppler Effect
Answer: The apparent change in the frequency of a moving object

Question: Gas
Answer: Gas has an indefinite shape and indefinite volume

Question: Insulator
Answer: No electricity can pass through


Question: What is temperature
Answer: Temperature is the measure of average kinetic energy of the molecules of a substance

Question: What is heat?
Answer: Thermal energy that you can give away

Question: What is the freezing and boiling points of water in *C and *F?
Answer: Celsius:
Freezing- 0
Boiling- 100

Freezing - 32

Question: What can happen when you heat a substance?
Answer: 1. Expand
2. Raise it's temperature
3. Change it's state

Question: Explain how a good thermos is designed to minimize all forms of heat transfer.
Answer: A thermos is designed with a glass outer layer and thin inner layer to create a vacuum. The vacuum reduces heat transfer from wall to wall through convection. The silver shiny inside is there for reflection to prevent heat transfer by radiation


Question: What are the two types of waves?
Answer: 1. Longitudinal
2. Transverse

Question: What can humans hear between?
Answer: 20 Hz and 20 kHz

Question: What can happen when light hits an object?
Answer: 1. Absorbed
2. Reflected
3. Refracted

Question: What are the two types of lenses?
Answer: 1. Concave
2. Convex

Question: Explain the difference between light and sound waves.
Answer: A light wave is a type of electromagnetic wave.

A sound wave is the vibrations that pass through an object or material.


Question: Explain how an electric generator works.
Answer: An electrical generator takes mechanical energy and converts it into electrical energy

Question: Explain the difference between series and parallel circuits. 
Answer: Series circuit- same voltage and current passes through all of the resistances

Parallel circuit- same voltage passes through each resistance, but the current through each resistance may vary.

Question: Explain the difference between AC and DC current
Answer: AC- electrons vibrate back and forth

DC- electrons move through the circuit, returning to where they started. Current is produced by a battery

Question: What is electricity?
Answer: Electricity is moving electrical charges

Question: What is current?
Answer: Rate of flow of electric charge


Question: How many poles does a magnet have?
Answer: 2: north and south

Question: Explain how the earth is like a large magnet
Answer: The earth is surrounded by a magnetic field that interacts with electrically charged or magnetized matter

Question: Do magnetic poles repel or attract
Answer: Repel

Question: What grade are you going to get on this exam?
Answer: A+++++

Question: What are magnetic fields caused by?
Answer: Moving electric charges