Thermal Energy Transfer (DP IB Physics: HL)

Thermal radiation is emitted by all bodies with an absolute temperature. It is often modelled using an idealised ‘black body’.

The spectrum of radiation emitted by a sample of glacier ice is examined. The ice is at a temperature of –55 ºC.

The average albedo of clean snow is 0.9. The average albedo of the glacier ice is 0.25.

The average intensity of radiation incident on the glacier is 4.7 kW h m⁻² during the summer and 0.23 kW h m⁻² during the winter, but these values are expected to rise as the climate changes.

When the snow melts and exposes the glacier ice beneath the surface albedo falls. This process is being accelerated. Explain how this acceleration affects global warming.

An industrial kiln is used for ‘firing’ ceramic and pottery items at very high temperatures.

The kiln emits electromagnetic radiation of peak wavelength, λ_max = 3.50 × 10⁻⁶ m.

The kiln has a surface area of 160 m².

The large kiln is compared to a smaller model with a surface area of 120 m² and a lower operating temperature of 710 K. The smaller kiln is made from the same materials and can also be treated as an ideal black body.

The working areas and people around kilns need to be protected from the high levels of heat energy emitted.

A planned Mars Rover will be powered using several solar panels each with dimensions of 2800 × 5900 mm. The equipment is tested on Earth at a point where the albedo of Earth’s atmosphere is 0.310.

The radiant power of the Sun is 3.90 × 10²⁶ W and the average radius of Earth’s orbit around the Sun is 1.50 × 10¹¹ m.

An astronomer uses the following data for a simple climatic model of Mars without an atmosphere:

Orbital radius between Mars and the Sun = 2.3 × 10¹¹ m
Absorbed solar radiation = 493 W m^–2

A regular cylinder is made up from two materials, X and Y. The cylinder’s dimensions are uniform throughout X and Y. The cylinder is placed in contact with a hot and cold source such that energy is conducted between them.

[2]

[2]

The following data are available for two metallic elements.

         Assume that each metal atom contributes one free electron.

It is very common at the coast for beaches to experience onshore winds during the day and offshore winds at night.

A satellite orbiting Earth has a malfunction, with some of its external components overheating.

Scientists modelling climate change are considering the effects of a range of actions on a global scale.

One possible model theorises an Earth with no atmosphere.

Energy flow diagrams can be used to represent energy transfers, making them clearer to understand.

Data available:
Incident solar radiation = 350 W m^–2
Absorbed solar radiation = 250 W m^–2

The average solar radiation reaching the surface can be found using the following equation:

Average intensity at the surface, I =  

Where α is albedo and S is the solar constant.

The spectrum of radiation emitted by a sample of glacier ice is examined.

One possible model of climate change is that the Earth will eventually have no atmosphere. 

A team of engineers are designing solar panels to power a Mars Rover on the surface of Mars.

[2]

A planned Mars Rover will be powered using several solar panels each with dimensions of 2700 × 4900 mm. The equipment is tested on Earth at a point where the albedo of Earth’s atmosphere is 0.390. The following additional information is available: 

• The radiant power of the Sun is 3.90 × 10²⁶ W
• The average radius of Earth’s orbit around the Sun is 1.50 × 10¹¹ m
• Orbital radius between Mars and the Sun = 2.3 × 10¹¹ m
• Absorbed solar radiation on Mars = 493 W m^–2

Determine the ratio

 .

Where P_M is the power of solar radiation incident on the solar panel on Mars and P_E is the power of solar radiation incident on the solar panel on Earth.

[6]

A regular cuboid is made up of two materials, P and Q. The cuboid’s dimensions are uniform throughout P and Q. The cylinder is placed in contact with a hot and cold source such that energy is conducted between them.

[1]

[1]

The following data are available for two metallic elements.

A car engine has a malfunction with some of its internal components overheating. 

An industrial kiln is used for ‘firing’ ceramic and pottery items at very high temperatures.

The kiln emits electromagnetic radiation of peak wavelength, λ_max = 3.75 × 10⁻⁶ m and has a surface area of 150 m².