Hello,
It's D! hope I helped.
Answer:
Frequency, 
Explanation:
Wavelength of a light wave is 450 nm. It is required to find the frequency of this light wave. The speed of light is given by c. So,

f is the frequency of this light

So, the frequency of this light is
.
Physical change = changes the physical properties (more commonly known as it's look)
Chemical change = changes the chemical properties into an entire new chemical form
Examples of physical change would be melting ice cubes or sugar cubes.
Examples of chemical change would be cooking eggs or burning paper because you're changing its chemical properties.
Answer:
B. 47-54 miles/hour
Explanation:
Gale is a strong wind which is depicted by red warning flag. According to U.S. National Weather Service gale is a sustained surface wind. It is also used to refer winds from tropical coastal areas.
On the basis of force of wind gale is divided in four groups:
- Near gale - 32-38 mph
- Gale - 39-46 mph
- Strong gale - 47-54 mph
- Storm - 55-63 mph