Physics Flashcards
Where does a muscular force come from?
It comes from the expanding and contracting of muscle tissue
How is an elastic force produced?
It is produced by any bent or stretched object that returns to its original shape
What does friction do?
Friction opposes motion whenever two surfaces are touching
What is Gravity?
Gravity is the force of attraction between two objects
Equal forces applied in opposite directions are said to be ____________ forces
Balanced
An unbalanced force cause an object at rest to do what?
To start moving
What does an unbalanced force cause
Acceleration
What is a force
A Force is any cause of a change in motion
What is an unbalanced force
A force that causes a change in motion
Which forces are acting on a parked car
Gravity and gasses
Who made observations about forces on moving or unmoving objects
Sir Isaac Newton
What does the first law of motion states
- An object at rest remains at rest unless acted upon by an unbalanced force
- An object in motion continues to move at a constant speed in a straight line unless acted upon by an unbalanced force
What is Inertia
The tendency of an object to oppose a change in motion
What is a centripetal force
The inward force that keeps an object moving in a circle
What are riding a bicycle you suddenly step on the brakes explain why you feel thrown back slightly
Because of inertia and because of an unbalanced force you have a change in speed and direction
What is heat
A form of energy that usually results in a temperature rise in a substance or a object. OR
The energy transferred between material or parts of a material that have different temperature
What are the sources of heat
Sun
Light
Television
Fire
What is temperature
A measure of how hot or cold something is. OR
the measure of the average kinetic energy in an object
What are three types of heat transfers
Conduction
Convection
Radiation
What is conduction
The transfer of energy from molecule to molecule by collision
What is Convection
The transfer of energy by the flow of a liquid to a gas
What is Radiation
The transfer of energy by electromagnetic waves
The flow within a fluid is due to the changes in density is called _________
Convection Current
A furnace heats water to boil. The steam moves through baseboard types. Energy from the steam is transferred through the air In a room by ______and ______
Convection and radiation
The effectiveness of heating systems depend on ___________
On the use of the insulating material such as foam helps to maintain heat
You cannot measure heat directly but_________
You can measure the changes in temperature
How much heat do substances that warm up slowly absorb
Large amounts for each degree the temperature rises
When a substance cools off, it releases ________
Heat
Substances that cool slowly use large amounts of heat for ___________
Each degree the temperature drops
Each material has its own specific because
It takes different amounts of heat to change the temperature of equal masses of different substances
What is specific heat measured in
Joules/Grams *C
What is the formula for the amount of heat a substance absorbs
Mass x temperature x specific heat
M x 🔼t x cp
What is the law of conservation
When you heat an object it gains energy. The heat loss and heat gain is because two or more substances are related
What happens to the changes of state when a substance cools down
They are reversed
What makes a material change its State?
Heat gain or heat loss
When an ice cube reaches 0 degrees Celsius what happens
It keeps absorbing heat but the temperature stops rising
Why does the temperature stop rising even though the ice is gaining heat
The ice cube melting the absorbed heat enables the molecules of the ice to breakaway form their crystal structure causing the Temperature not to rise until all of the ice is melted
What is heat of fusion
The heat needed to change one gram of material from a solid to a liquid
The heat needed to change one gram of a liquid into a gas is called
Heat of vaporization
A blue flame gives more heat than a _____ flame
Yellow
A bright yellow flame gives more light than a ______
Yellow flame
What is a blue flame better for cooking than a yellow flame
Cooking with a big yellow flame means you are wasting fuel or gas since they carry less heat
What is the heat of fusion and heat of vaporization for water, aluminum, Iron, Copper, Silver,mercury and lead
Water - 334, 2254 Aluminum -393, 10544 Iron-33, 6694 Copper-205, 4812 Silver-105.8, 2364 Mercury-11.8,295.4 Lead-22.9, 806
Force exert per unit area of surface
Pressure
A gas exert a force on the wall is contained by
Gas expansion
