1st Law Thermodynamics

What does the 1st Law of Thermodynamics state?

• Energy can be created and destroyed.

• Energy is not conserved in the universe.

• Energy can neither be created nor destroyed, only converted from one form to another.

• Power generation creates energy from nothing.

Which of the following is an example of an open system?

• A pressure cooker with the lid tightly sealed

• A closed can of soda

• An insulated thermos

• A boiling pot of soup without a lid

Which of the following best represents a closed system?

• A mug of coffee sitting on a desk

• A sealed soda can

• A solar panel collecting sunlight

• A classroom with an open door

Which situation is the best example of an isolated system?

• A pot of soup with the lid on, placed on a stove

• A car engine running

• An ice cube in a cooler with thick insulation

• A cup of tea in an open room

Radiation requires a medium (like air or water) to transfer heat.

• True

• False

Why does a metal spoon placed in hot soup become warm?

• Radiation of heat from the soup

• Heat moves by air currents

• Heat is conducted from the soup to the spoon

• Spoon emits energy waves

What characterizes the transfer of energy as work?

• Uniform motion of atoms in the surroundings

• Chaotic motion of atoms in the surroundings

• Increase in temperature only

• Random vibration of molecules

What happens to the work done by the system during free expansion?

• It increases

• It becomes negative

• It equals zero

• It is undefined

Based on the equation w=−PextΔV, which of the following will result in greater work done by the system?

• Low external pressure and small volume change

• High external pressure and large volume change

• Zero external pressure

• No change in volume

Mechanical equilibrium during expansion is defined as:

• Internal pressure being much higher than external pressure

• Constant temperature and volume

• Maximum heat loss

• External pressure equal to internal pressure