The correct answer is D. Amount of time and area of physical contact between the substances.
Explanation:
Heat transfer refers to the flow of thermal energy or heat between two or more objects. This process involves multiple factors and implies heat from the hottest object goes to the coldest one until there is an equilibrium. To begin, heat transfer depends on the amount of thermal energy in the objects because objects must have a different amount of thermal energy for heat to flow.
Besides this, the amount of energy that flows depends on the time and the contact between the substances of objects. Indeed, objects need to be in contact or close to each other for heat to transfer, and the time needs to be enough for the process to occur. For example, if you place a pot over the fire just for a few seconds it is likely the heat transferred is minimal, which does not occur if you leave the pot more time. At the same time if the pot is in close contact with fire more heat will be transferred.-
A standing wave is the result of a reflection.
The kinetic energy of the phone right before it hits the ground is 9J.
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Kinetic energy of the phone</h3>
The kinetic energy of the phone right before it hits the ground is calculated as follows;
K.E = ¹/₂mv²
where;
- m is mass of the phone
- v is velocity of the phone
K.E = ¹/₂(0.08)(15)²
K.E = 9 J
Thus, the kinetic energy of the phone right before it hits the ground is 9J.
Learn more about kinetic energy here: brainly.com/question/25959744
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Answer:
Explanation:
Given that,
Frequency of radio signal is
f = 800kHz = 800,000 Hz.
Distance from transmitter
d = 8.5km = 8500m
Electric field amplitude
E = 0.9 V/m
The average energy density can be calculated using
U_E = ½•ϵo•E²
Where ϵo = 8.85 × 10^-12 F/m
Then,
U_E = ½ × 8.85 × 10^-12 × 0.9²
U_E = 3.58 × 10^-12 J/m²
The average electromagnetic energy density is 3.58 × 10^-12 J/m²
