Answer:
A) radiation.
Explanation:
Hello,
In this case, heat transfer from a body with a high temperature to a body with a lower temperature may occur when the bodies are not in direct physical contact with each other or when they are separated in space and it is is called heat radiation. Solids, liquids, or gaseous substances are able to emit energy via a process of electromagnetic radiation because of vibrational and rotational movement of their molecules and atoms.
Hence, since the camp fire is not in contact with the marshmallow and it still cooks it, we can infer that the mechanism of heat transfer is A) radiation. Moreover, both conduction and convection occur when the bodies are in contact.
Regards.
The heat absorbed is calculated using the following equation:
Q = mCΔT
Q = heat absorbed
m = mass = 66 g
C = specific heat of iron = 0.449 J/g.°C
ΔT = temperature change = 20 - 7 =13°C
Therefore,
Q = 66*0.449*13 = 385.242 J
The tension in the swing's chain at the bottom of the swing is 178.35 N.
The given parameters:
- Mass of the girl, m = 27 kg
- Speed of the girl, v = 3 m/s
- Radius of the circle, r = 4 m
The tension in the swing's chain at the bottom of the swing is calculated as follows;
Thus, the tension in the swing's chain at the bottom of the swing is 178.35 N.
Learn more about tension in vertical circle here: brainly.com/question/19904705
