Heat Engines

How much is the energy received from the hot reservoir?

• 120 J

• 480 J

• 360 J

• 580J

Tags

NGSS.HS-PS3-4

In energy transformations, "wasted energy" usually takes what form?

• heat

• chemical energy

• light

• sound waves

Tags

NGSS.HS-PS3-4

Which is a device that converts heat energy into mechanical energy?

• Refrigerator

• Heat engine

• Thermostat

Tags

NGSS.HS-PS3-3

Four strokes of the engine cycle, in order:

• compression, exhaust, power, intake

• ignition, compression, power, exit

• intake, compression, power, exhaust

Tags

NGSS.HS-PS3-4

What happens to the gas if it is heated inside the engine’s cylinder?

• The gas expands

• The gas contracts

• The gas remains the same

• The gas ignites

Tags

NGSS.MS-PS1-4

Can we consider heat engine 100% efficient? Why?/Why not?

• No, because some of the gases are exhausted into the environment

• Yes, because it converts all energy

• No, because it loses energy to friction

• Yes, because it is perfectly designed

Tags

NGSS.HS-PS3-4

What is the primary reason a heat engine cannot achieve 100% efficiency?

• Because it is designed for maximum output

• Because some energy is lost as waste heat

• Because it uses mechanical energy

• Because it operates at low temperatures

Tags

NGSS.HS-PS3-4

How does the first law of thermodynamics apply to heat engines?

• The first law of thermodynamics indicates that all energy input is converted to useful work without any losses.

• The first law of thermodynamics applies to heat engines by stating that the energy input (heat) minus the energy output (waste heat) equals the work done by the engine.

• The first law of thermodynamics states that energy cannot be created or destroyed, but it does not apply to heat engines.

• 
  Heat engines operate by converting work into heat, according to the first law of thermodynamics.

Tags

NGSS.HS-PS3-3

NGSS.HS-PS3-4

In exhaust stroke, what happens to the piston and the mixture of gases?

• The piston moves down, the exhaust valve opens and the burned gas is expelled

• The piston moves up, the exhaust valve closes

• The piston remains still, gases are compressed

• The piston moves down, gases are ignited

Tags

NGSS.HS-PS2-1

During the intake stroke, what happens to the piston and the air-fuel mixture?

• The piston moves down, expelling the mixture

• The piston remains still, the mixture is ignited

• The piston moves up, compressing the mixture

• The piston moves down, drawing in the mixture

Tags

NGSS.HS-PS2-1