Science concepts Flashcards
Mass (kg) x Acceleration = ???
Force (newton)
Mass (kg) x Gravitational Field Strength (N/kg) = ???
Weight (newton)
FD = M means?
Force (N) x perpendicular distance from pivot (m) = Moment of force
How is mass measured?
Using a beam balance of electronic balance
How is weight measured?
Using a spring balance
In order for work to be done, what are the conditions?
When a force acts on an object, the object must move in the same direction as the force.
W = F x D ?
Work done = Force x Distance moved in the direction of the force
Force (N) x Distance moved in the direction of the applied force = ?
Work done
Force SI unit:
Newton (N)
Mass SI unit
kilogram (kg)
Weight SI unit
Newton (N)
Distance SI unit
metre (m)
Pressure SI unit
Pascal (Pa)
Define pressure:
It is the amount of force acting perpendicularly on a unit area
Force/Area = ??
Pressure
What is the pressure exerted by the air in the earth’s atmosphere called?
Atmospheric pressure
What is the moment of a force?
It is the turning effect of a force
What is the definition of gravitational field strength
Gravitational force per unit mass
The greater the mass of an object?
The greater its weight
What energy does an object possess at its highest point?
Gravitational Potentail Energy
Heat transfer stops when?
When the substances reaches thermal equilibrium
Define energy
- It cannot be created nor destroyed.
- It can be converted from one to another.
- The total energy in an isolated system remains constant
Define Gravitational field strength
It is defined as the gravitational force in newtons that acts on a mass of one kilogram.
What are examples of renewable sources of energy?
- Biofuels
- Geothermal energy
- Hydroelectric energy
- Wind energy
- Solar energy
Work done SI unit
Joule (J)
To convert square centimeters to square meters, you need to?
divide by 10,000 (100x100)
How does a bimetallic strip work?
- Expands more so the top strip of the bimetallic strip is put on the outside of the curve (bent back and force other strip to follow)
- Contracts more so the top strip of the bimetallic strip is put on the inside of the curve (pull in like reigns)
To convert pascals (Pa) to kilopascals (kPa), you need to?
divide the pressure in pascals by 1,000
What is the worst heat conductor?
A vaccum. It cannot conduct heat since there are no particles in a vaccum.
Define conduction
It is the transfer of heat from a hotter to colder region through contact between the two sources.
Define conduction (upper sec)
It is a process whereby thermal energy is transferred
through collision of particles.
How is heat transfered by solids ONLY!
Molecular vibration
How is heat transfered by solids, liquids and gases
Collision of particles
Why are solids better conductors than liquids/ gases?
Since conduction of heat occurs when two sources are in contact
What is thermal conductivity?
A measure of the ability of a matter to conduct heat
