G9-Q4-SUMMATIVE TEST #5 (HEAT, WORK, ENERGY)

Which of the following statements best describes the first law of thermodynamics?

• Entropy of an isolated system always increases.
• Heat cannot be completely converted into work in a cyclic process.
• Energy cannot be created or destroyed, only transferred or converted.
• The enthalpy of a system is always constant.

In the context of the first law of thermodynamics, what does the equation ΔU = Q - W represent?

• Change in entropy equals heat minus work.
• Change in enthalpy equals heat minus work.
• Change in internal energy equals heat minus work.
• Change in Gibbs free energy equals heat minus work.

In the context of the first law of thermodynamics, what does the equation ΔU = Q - W represent?

• Change in entropy equals heat minus work.
• Change in enthalpy equals heat minus work.
• Change in internal energy equals heat minus work.
• Change in Gibbs free energy equals heat minus work.

A tricycle driver in Manila exerts a force to pedal his vehicle, moving passengers down a street. Identify the physical process that is happening when the driver's force causes the tricycle to move a certain distance.

(a)  

In a typical 'carinderia' (local eatery) in your neighborhood, the cook places a metal pot of water over a gas stove flame. Identify the form of energy transfer that is taking place, specifically the transfer of thermal energy from the hotter flame to the cooler water, resulting in an increase in the water's temperature.

(a)  

The first law of thermodynamics states that in an isolated system, the total amount of energy remains constant, even if it changes forms.

• TRUE
• FALSE

The first law of thermodynamics implies that it is possible to create a machine that produces work without consuming any energy.

• TRUE
• FALSE

A "kalan de uling" (charcoal stove) is used to cook rice in a "kawali" (wok). Which of the following energy transfers are taking place? (Check all that apply)

• Heat transfer from the burning charcoal to the kawali.
• Electrical energy being converted to light.
• Chemical energy stored in the charcoal being converted to thermal energy.
• Sound energy from the crackling charcoal.

A student in a "barangay" (local community) gym lifts a barbell. Which of the following are involved in this process? (Check all that apply)

• Heat transfer from the barbell to the student's hands.
• Work being done by the student against gravity.
• Chemical energy from the student's muscles being converted to mechanical energy.
• Light energy being emitted from the barbell.

Imagine a sunny day at the park. Draw a picture that shows how energy is transformed as a person rides a bicycle. Be sure to include the following elements in your drawing: heat, work, and energy.

Additional Tips:

Use arrows to show the direction of energy transfer.

Label the different forms of energy in your drawing.

Get creative and add details to your picture to make it more engaging.