Ask question

Ask question

All categories

3 years ago

5

Why do we see black? Is light being admitted reflected or absorbed or transmitted

1 answer:

Diano4ka-milaya [45]3 years ago

4 0

Answer:When white light strikes an object, each individual frequency of light is transmitted, reflected, or absorbed, depending on the properties of the surface molecules. If all frequencies are absorbed by the object, then it appears black. If all frequencies are reflected, then it appears white.

Explanation:

You might be interested in

Elements in the same group/familly of the periodic table are similar in what way

olga nikolaevna [1]

Their chemicals and their reactions, hope I helped

6 0

4 years ago

If the frequency of a wave is 0.25 Hz, what is its period?

aleksandr82 [10.1K]

Answer:

C

Explanation:

frequency = 1 / period

so

frequency = 0.25

0.25 = 1 / period

1 / 0.25 = period

4 s = period

it is not 4 Hz because period is the time taken

so the answer is C

hope this helps ,please mark it

4 0

3 years ago

011 10.0 points

Sedbober [7]

<h2>The temperature of the air is 66.8° C</h2>

Explanation:

From the Newton's velocity of sound relationship , the velocity of sound is directly proportional to the square root of temperature .

In this case The velocity of sound = frequency x wavelength

= 798 x 0.48 = 383 m/sec

Suppose the temperature at this time = T K

Thus 383 ∝ $\sqrt{T}$ I

The velocity of sound is 329 m/s at 273 K ( given )

Thus 329 ∝ $\sqrt{273}$ II

Dividing I by II , we have

$\frac{383}{329}$ = $\sqrt{\frac{T}{273} }$

or $\frac{T}{273}$ = 1.25

and T = 339.8 K = 66.8° C

4 0

4 years ago

Help me pleaseeeeee due. Today

sergeinik [125]

Answer:

1. geothermal

2. nuclear

3. biofuel

4 0

3 years ago

Read 2 more answers

A 55 kg cheerleader uses an oil-filled hydraulic lift to hold four 110 kg football players at a height of 1.0 m. If her piston i

AVprozaik [17]

Answer:

$D = 55.2 cm$

Explanation:

As we know that the total mass of the all four players is given as

$M = 4\times 110$

$M = 440 kg$

diameter of the piston of cheer leader is given as

$d_1 = 16 cm$

are of cross-section is given as

$A_1 = \pi r^2$

$A_1 = \pi(0.08)^2 = 0.02 m^2$

mass of the cheer leader is given as

m = 55 kg

so the pressure due to cheer leader is given as

$P_{in} = \frac{mg}{A_1}$

$P_{in} = \frac{55 \times 9.81}{0.02}$

$P_{in} = 26835 Pa$

Now on the other side pressure must be same

so we have

$\frac{Mg}{A} + \rho gH = P_{in}$

$\frac{440 \times 9.8}{A} + (900)(9.8)(1) = 26835$

$A = 0.24 m^2$

$\pi r^2 = 0.24$

$r = 0.276 m$

so diameter on the other side is given as

$D = 2 r$

$D = 55.2 cm$

8 0

3 years ago