RADIATION
There are three types of heat transfer or heat propagation; conduction, convection and radiation. Heat transfer is the process by which heat projects externally however, depending on the temperature and pressure. Also called the movement of heat from a low temperatured state which increases as heat progresses.
Conduction is the heat transfer by contact, immediate contact.
Convection is the transfer of heat through air and water.
<span>Radiation is the transfer of heat regardless of the presence of atoms or particles.<span>
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m₁ = mass of sample of copper = m₂ = mass of sample of aluminum = 5 g
T = initial temperature of copper = initial temperature of aluminum
T₁ = final temperature of copper
T₂ = final temperature of aluminum
c₁ = specific heat of copper = 0.09 cal/g°C
c₂ = specific heat of aluminum = 0.22 cal/g°C
Since both receive same amount of heat, hence
Q₁ = Q₂
m₁ c₁ (T₁ - T) = m₂ c₂ (T₂ - T)
(5) (0.09) (T₁ - T) = (5) (0.22) (T₂ - T)
T₁ - T = (2.44) (T₂ - T)
Change in temperature of copper = (2.44) change in temperature of aluminum
hence the correct choice is
c. The copper will get hotter than the aluminum.
The formula of density is given by
Density = Mass ÷ Volume
We have:
Mass = 1.989 × 10³⁰ kg
Volume =
=
km³
Density =
=1.13×10¹⁸ kg/km³
Converting 1.13 × 10¹⁸ kg/km³ to g/cm³
1.13 × 10¹⁸ kg = 1.13 × 10¹⁸ × 10³ = 1.13 × 10²¹ grams
1 km³ = 1 × 10⁶ cm³
(1.13 × 10²¹) ÷ 10⁶ = 1.13 × 10¹⁵ gr/cm³
Answer: Density 1.13 × 10¹⁵ gr/cm³
Instead of asking this question go and study
