Question

1) If you want to know whether radiation is potentially dangerous or harmless, the most important question to ask is

choose one:

whether the dose was higher than the threshold

what type of radiation it is (alpha, beta, gamma, etc.)

how long ago the radiation was created

whether the radiation came from radioactive decay

whether it is ionizing

2) A car engine cannot be made which simply extracts energy from the air around it to run. Why not?

choose one:

The air contains very little entropy.

The rate at which it extracted energy from the air would be too low.

The air contains very little thermal energy.

Thermal Energy cannot be converted into other forms.

The engine would not have a temperature difference across which to run.

3) Which of the following devices requires energy to be turned into heat before it can be utilized?

choose one:

Pneumatics

Hydraulics

Motor

Servo

Engine

Answer 1

1.)  If you want to know whether radiation is potentially dangerous or harmless, the most important question to ask is,

whether the dose was higher than the threshold

what type of radiation it is (alpha, beta, gamma, etc.) , because Alpha radiation is the most dangerous , but beta and gamma are not as dangerous .

2.) Because, The engine would not have a temperature difference across which to run.

3.) Engine, Heat engines, like the internal combustion engine, burn a fuel to create heat which is then used to do work.