Answer:
baking the cake batter
Explanation:
Baking the cake batter will indicate that chemical change has occurred here. What is a chemical change?
- A chemical change is one in which a new kind of matter is formed.
- It is usually accompanied by energy either evolution or absorption of energy in form of heat or light or both.
- The process is irreversible.
- When the batter bakes, a new substance different from the cake mix is obtainable.
- We cannot get back the ingredient from this baked cake. It is impossible.
- This is good indicator of chemical change.
Answer:
1) f= 8.6 GHz
2) t= 0.2 ms
Explanation:
1)
- Since microwaves are electromagnetic waves, they move at the same speed as the light in vacuum, i.e. 3*10⁸ m/s.
- There exists a fixed relationship between the frequency (f) , the wavelength (λ) and the propagation speed in any wave, as follows:

- Replacing by the givens, and solving for f, we get:

⇒ f = 8.6 Ghz (with two significative figures)
2)
- Assuming that the microwaves travel at a constant speed in a straight line (behaving like rays) , we can apply the definition of average velocity, as follows:
where v= c= speed of light in vacuum = 3*10⁸ m/s
d= distance between mountaintops = 52 km = 52*10³ m

⇒ t = 0.2 ms (with two significative figures)
When a light wave strikes an object, it can be absorbed, reflected, or refracted by the object. All objects have a degree of reflection and absorption. ... In the natural world, light can also be transmitted by an object. That is, light can pass through an object with no effect (an x-ray, for example).
I think the answer to this problem I believe would probably be B. learned optimism. I think it's the closest answer...I THINK