Answer:
1. Hot air is less dense and has moved upward allowing cool air to move downward which is less dens
(Convection current)
2. The ceiling has transferred heat to him by radiation.
Explanation:
During the day when air is heated as a result of the ceiling transferring heat to it, it becomes less dens and it gains energy, which make it lighter in weight than cooler air, this hot air moves upward allowing cooler air to move downward.
Answer:0.061
Explanation:
Given

Temperature of soup 
heat capacity of soup 
Here Temperature of soup is constantly decreasing
suppose T is the temperature of soup at any instant
efficiency is given by



integrating From
to 


![W=c_v\left [ T-T_C\ln T\right ]_{T_H}^{T_C}](https://tex.z-dn.net/?f=W%3Dc_v%5Cleft%20%5B%20T-T_C%5Cln%20T%5Cright%20%5D_%7BT_H%7D%5E%7BT_C%7D)
![W=c_v\left [ \left ( T_C-T_H\right )-T_C\left ( \ln \frac{T_C}{T_H}\right )\right ]](https://tex.z-dn.net/?f=W%3Dc_v%5Cleft%20%5B%20%5Cleft%20%28%20T_C-T_H%5Cright%20%29-T_C%5Cleft%20%28%20%5Cln%20%5Cfrac%7BT_C%7D%7BT_H%7D%5Cright%20%29%5Cright%20%5D)
Now heat lost by soup is given by

Fraction of the total heat that is lost by the soup can be turned is given by

![=\frac{c_v\left [ \left ( T_C-T_H\right )-T_C\left ( \ln \frac{T_C}{T_H}\right )\right ]}{c_v(T_C-T_H)}](https://tex.z-dn.net/?f=%3D%5Cfrac%7Bc_v%5Cleft%20%5B%20%5Cleft%20%28%20T_C-T_H%5Cright%20%29-T_C%5Cleft%20%28%20%5Cln%20%5Cfrac%7BT_C%7D%7BT_H%7D%5Cright%20%29%5Cright%20%5D%7D%7Bc_v%28T_C-T_H%29%7D)




Explanation:
This should be of help:
An atom is made up of three subatomic particles:
- Protons are the positively charged particles.
- Electrons are the negatively charged particles.
- Neutrons do not carry any charges.
A neutral atom is an atom that has not lost or gained any amount of electrons.
In a neutral atom;
the number of protons and electrons are the same
Usually atoms are designated this way:
ᵃₙX
where X is the symbol of the atom
a is the mass number of the atom
n is the atomic number of the atom
The mass number = number of protons + number of neutrons
Atomic number = number of protons
Note; atomic number is the same as the number protons and the number of electrons in a neutral atom.
Use this guide to solve the problem
Learn more:
Atomic number brainly.com/question/5425825
#learnwithBrainly
the answer is c) the speed and direction of travel must be constant