Unit EM - energy based model for interactions

types of energy

KE, CPE, TE

what is kinetic energy

energy an object has because of its motion

What is chemical potential energy

energy that has the potential to produce other types of energy

what is thermal energy

the warming up (increase in temp) of an object

efficiency of a system formula

𝜂=(Useful Energy Output/Total Energy Input) ×100

statement of conservation

energy transferred into system from sun = increase in TE of surroundings + increase in energy of sound receivers

2 objects act on or influence each other to cause (blank)

effect

transferred from energy (blank) to energy (blank), one increase one decrease

giver, receiver

what are the 5 interaction types

contact push/pull, heat, electric circuit, light, sound

what are the 3 mechanisms for heat interactions

conduction, convection, IR

what is conduction

when warmer and cooler objects are actually in direct contact with each other, or when one part of a single object warmer than the other

what is convection

when a gas or liquid is heated by being in contact with a warm object, then the warm gas/liquid moves somewhere else (usually up) and warms a cooler object by coming in contact with it

what is IR

when 2 objects have different temperatures and there is a direct line of sight between them, there is a net transfer of energy from the warmer object to the cooler one via the IR that can pass through them

what is an open system

allows both energy and physical matter to cross freely in and out

what is a closed system

allows energy to cross through it but blocks and matter from entering or leaving

all energy sources (blank) when they operate

warm

what is the law of conservation of energy

energy is never destroyed but transferred and transformed into other objects. If energy decreases somewhere, it must increase by the same amount somewhere else.

statement of conservation outline

decrease in (blank) of (blank) = increase in (blank) of (blank) + Increase in (blank) of (blank)

particular device is known to be 40% efficient. If 30,00 J were transferred into the device, how much useful energy is transferred out

30,000 × 0.40=12,000 J

particular device is known to be 40% efficient. If 30,00 J were transferred into the device and 12,000 J of useful energy was transferred, how much non-useful energy is transferred out into the surroundings

30,000 - 12,000 =18,000 J