1) <span> What is heat? the answer is B because heat is a form of energy</span>
Answer:
Gay-Lussac’s law, because as the pressure increases, the temperature increases
Explanation:
First of all, we can notice that the volume of the tank is fixed: this means that the volume of the air inside is also fixed.
This means that in this situation we can apply Gay-Lussac's law, which states that:
"for a gas kept at constant volume, the pressure of the gas is proportional to the absolute temperature of the gas".
Mathematically:

where p is the pressure in Pascal and T is the temperature in Kelvin.
In this case, the tank is filled with air: this means that the pressure of the gas inside the tank increases. And therefore, according to Gay-Lussac's law, the temperature will increase proportionally, and this explains why the tank gets hot.
As the intensity increases the energy increases.
Answer:
C. the energy of the sound wave increases
Answer:
Twice as fast
Explanation:
Solution:-
- The mass of less massive cart = m
- The mass of Massive cart = 2m
- The velocity of less massive cart = u
- The velocity of massive cart = v
- We will consider the system of two carts to be isolated and there is no external applied force on the system. This conditions validates the conservation of linear momentum to be applied on the isolated system.
- Each cart with its respective velocity are directed at each other. And meet up with head on collision and comes to rest immediately after the collision.
- The conservation of linear momentum states that the momentum of the system before ( P_i ) and after the collision ( P_f ) remains the same.

- Since the carts comes to a stop after collision then the linear momentum after the collision ( P_f = 0 ). Therefore, we have:

- The linear momentum of a particle ( cart ) is the product of its mass and velocity as follows:
m*u - 2*m*v = 0
Where,
( u ) and ( v ) are opposing velocity vectors in 1-dimension.
- Evaluate the velcoity ( u ) of the less massive cart in terms of the speed ( v ) of more massive cart as follows:
m*u = 2*m*v
u = 2*v
Answer: The velocity of less massive cart must be twice the speed of more massive cart for the system conditions to hold true i.e ( they both come to a stop after collision ).
Light can be seen as an electromagnetic wave.
What happens when two waves, with the same frequency, superpose is called interference.
If at a certain point two waves arrive both with a crest, we have constructive interference and the amplitudes sum up, reaching the maximum value, resulting in bright spots.
If at a certain point one of the waves arrives with a crest and the other wave arrives with a trough, we have destructive interference, and the two amplitudes cancel out, resulting in dark spots.
Therefore, t<span>he dark bands on the wall are from destructive interference.</span>