P8 Flashcards
What type of radiation do warm objects primarily emit?
Infrared radiation
This can be detected using a thermal imaging camera.
How does the color of a heated metal rod indicate its temperature?
The hotter part glows yellow, the cooler part glows red, and if heated more, it glows bluish white.
What happens to the frequency and wavelength of radiation emitted as the temperature of an object increases?
The frequency increases and the wavelength decreases.
What is the relationship between the intensity of radiation and the temperature of stars?
A hot star has a higher intensity of radiation at higher frequencies compared to a cool star.
What happens to the temperature of an object that emits less radiation than it absorbs?
The temperature increases.
What happens to the temperature of an object that emits more radiation than it absorbs?
The temperature decreases.
How does the Earth’s atmosphere influence its temperature?
It reflects some radiation back to Earth, affecting the balance of absorbed and emitted radiation.
What is the effect of increasing greenhouse gases in the Earth’s atmosphere?
It leads to an increase in the Earth’s temperature.
Fill in the blank: The temperature of an object depends on the balance of the radiation _______ and _______.
absorbed, emitted
What type of radiation from the Sun does the Earth absorb?
Infrared, visible light, and ultraviolet radiation.
In summer, why does a house heat up during the day and cool down at night?
Due to the balance of radiation absorbed from the Sun and emitted into space.
True or False: The graph of intensity of radiation against frequency for stars peaks at lower frequencies for hotter stars.
False.
What color indicates higher temperatures in thermal images?
Red indicates high temperature and blue indicates low temperature.
What is the peak frequency of radiation emitted by a cup of iced water compared to a Bunsen burner flame and a cup of tea?
Iced water < cup of tea < Bunsen burner flame.
Why do hotter stars emit blue rather than red light?
Because hotter objects emit radiation at higher frequencies.
