please check these for me:

What is the wavelength of microwaves of 3.0*10^9 Hz frequency?
a. 0.050m
b. 0.060m
c. 0.10 m
d. 0.20 m

C

If a light ray strikes a flat mirror at an angle of 30deg from the normal, the ray will be reflected at an angle of
a. 30deg from the mirror's surface
b. 60deg from the mirror's surface
c. 60deg from the normal
d. 90deg from the normal

B

Which of the following is NOT a primary subtractive color?
a. yellow
b. cyan
c. magenta
d. blue

D

When a light ray moves from air into glass, which has a higher index of refraction, its path is
a. bent toward the normal
b. bent away from the normal
c. parallel to the normal
d. not bent

A

how many focal points and focal lengths do converging and diverging lenses have?
a. two, one
b. one, two
c. one, one
d. two, two

A

All are correct. Congratulations! You are doing much better

a thimble is 32.0cm from a concave mirror. the focal point of the mirror I'd 11.0cm. where is the image located?

Here are the checks for the given questions:

1. The wavelength of microwaves can be calculated using the formula: wavelength = speed of light / frequency. Given the frequency is 3.0*10^9 Hz, we can substitute this value in the formula to get: wavelength = 3.0*10^8 m/s / 3.0*10^9 Hz = 0.1 m. Therefore, option C (0.10 m) is correct.

2. When a light ray strikes a flat mirror, the angle of incidence is equal to the angle of reflection. The angle of incidence is given as 30 degrees from the normal, so the reflected ray will also be at an angle of 30 degrees from the mirror's surface. Therefore, option A (30 degrees from the mirror's surface) is incorrect. The correct answer is option B (60 degrees from the mirror's surface).

3. The primary subtractive colors are cyan, magenta, and yellow. Blue is not a primary subtractive color. Therefore, option D (blue) is correct.

4. When a light ray moves from air into glass, with glass having a higher index of refraction, the ray is bent towards the normal. Therefore, option A (bent toward the normal) is correct.

5. Converging lenses have two focal points and one focal length, while diverging lenses have two focal lengths and one focal point. Therefore, option A (two focal points and one focal length) is correct.

To check the answers for the given questions, you need to apply the relevant concepts and formulas. Here's how you can do it:

1. Wavelength of microwaves:
The formula relating frequency (f) and wavelength (λ) is given by λ = c / f, where c is the speed of light in a vacuum (approximately 3.0 × 10^8 m/s).

To solve for the wavelength, substitute the given frequency (3.0 × 10^9 Hz) into the formula:
λ = (3.0 × 10^8 m/s) / (3.0 × 10^9 Hz) = 0.1 m

Comparing the calculated wavelength to the given options, we see that the wavelength is 0.1 m, which corresponds to option C.

2. Reflection of light from a flat mirror:
The law of reflection states that the angle of incidence (θi) is equal to the angle of reflection (θr). In this case, the incident angle (θi) is given as 30°.

Therefore, the reflected angle (θr) will also be 30°. Comparing this to the given options, we see that the reflected angle is 30° from the mirror's surface, corresponding to option A.

3. Primary subtractive colors:
The primary subtractive colors are cyan, magenta, and yellow. These colors are used in subtractive color mixing, where overlapping colors absorb light and create different color combinations.

Comparing the given options, we see that yellow is not a primary subtractive color, as it is a primary additive color. So the correct answer is option A.

4. Refraction of light from air into glass:
When light passes from one medium to another with a higher refractive index, it bends towards the normal. This is known as refraction.

Therefore, when light rays move from air into the glass, which has a higher index of refraction, its path is bent towards the normal. Hence, option A is the correct answer.

5. Focal points and focal lengths of lenses:
Converging lenses have two focal points, one on each side of the lens. Diverging lenses, on the other hand, do not have real focal points but can be said to have two virtual focal points, also on each side of the lens.

Therefore, the correct answer is option A, where converging lenses have two focal points and one focal length, while diverging lenses have two focal points and one focal length.