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3 years ago

Hair can be used to measure humidity. a. True b. False

Physics

1 answer:

Rainbow [258]3 years ago

4 0

A. True.

You can make a hygrometer using strands of hair.

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As microwave light travels through a liquid, it moves at a speed of 2.2 x 108 m/s. If the frequency of this light wave is 1.1 x

Alexandra [31]

λ = 2 m.

The easiest way to solve this problem is using the equation of frecuency of a wave f = v/λ, where v is the velocity of the wave, and λ is the wavelength.

To calculate the wavelength of a microwave light travels through a liquid, it moves at a speed of 2.2 x 10⁸ m/s. If the frecuency of the light wave is 1.1 x 10⁸ Hz, we have to clear λ from the equation f = v/λ:

f = v/λ -------> λ = v/f

λ = 2.2 x 10⁸ m/s / 1.1 x 10⁸ Hz

λ = 2 m (wavelength of the microwave)

7 0

3 years ago

What is the frequency of a wave that has a period of 50 seconds?

Yuliya22 [10]

Answer:

0.02 Hertz

Explanation:

7 0

2 years ago

The energy associated with the random motion of molecules or atoms within a substance is

Yuliya22 [10]

Answer:

technically B too but youre teachers not that smart so there you go

6 0

3 years ago

A 5000 kg open train car is rolling on frictionless rails at 22 m/s when it starts pouring rain. A few minutes later, the car’s

Phantasy [73]

Answer:

500 kg

Explanation:

It is given that,

The mass of a open train car, M = 5000 kg

Speed of open train car, V = 22 m/s

A few minutes later, the car’s speed is 20 m/s

We need to find the mass of water collected in the car. It is based on the conservation of momentum as follows :

initial momentum = final momentum

Let m is final mass

MV=mv

$m=\dfrac{MV}{v}\\\\m=\dfrac{5000\times 22}{20}\\\\=5500\ kg$

Water collected = After mass of train - before mass of train

= 5500 - 5000

= 500 kg

So, 500 kg of water has collected in the car.

3 0

3 years ago

(a) when rebuilding her car's engine, a physics major must exert 300 n of force to insert a dry steel piston into a steel cylind

Vilka [71]

There are some missing data in the text of the problem. I've found them online:
a) coefficient of friction dry steel piston - steel cilinder: 0.3
b) coefficient of friction with oil in between the surfaces: 0.03

Solution:
a) The force F applied by the person (300 N) must be at least equal to the frictional force, given by:
$F_f = \mu N$
where $\mu$ is the coefficient of friction, while N is the normal force. So we have:
$F=\mu N$
since we know that F=300 N and $\mu=0.3$ , we can find N, the magnitude of the normal force:
$N= \frac{F}{\mu}= \frac{300 N}{0.3}=1000 N$

b) The problem is identical to that of the first part; however, this time the coefficienct of friction is $\mu=0.03$ due to the presence of the oil. Therefore, we have:
$N= \frac{F}{\mu}= \frac{300 N}{0.03}=10000 N$

8 0

3 years ago