First Law of Thermodynamics

The study of how thermal energy is transformed into another types of energy is _________________________.

• Thermodynamics

• Power

• Temperature

The mathematical equation of the first law of thermodynamics is __________________.

• ΔU=W

• ΔU=Q

• ΔU=Q - W
  

The thermal energy entering the system from outside is called ________________.

• Work

• Heat

• Power

To find the change in thermal energy, we need to use ____

• ΔU = 𝑚𝐶∆𝑇

• ΔU = ∆𝑇

• ΔU = 𝐶∆𝑇

A kettle on fire receives 8000 J, the kettle kept shaking with 500 J work. Find the change in the kettle's thermal energy?

• 500 J

• 7500 J

• 8000 J

A saw used to cut a 1 Kg copper pipe, this caused 1°C raise in the pipe's temperature, how much work did the pipe receive from the saw? (Ccopper=385 J/(°C.Kg))

• 385 J

• 673 J

• 836 J

A saw used to cut a 1 Kg copper pipe, this caused 1°C raise in the pipe's temperature, how much work did the pipe receive from the saw? (Ccopper=385 J/(°C.Kg))

(a)  

The descriptive equation of the first law of thermodynamics is __________________.

How hard is this topic?

• Very easy

• Easy

• Hard

• Very hard

Draw what happens in each step.