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2 years ago

A group of hikers hear an echo 3.3 s after they shout. The temperature is 20◦C.

Physics

1 answer:

romanna [79]2 years ago

4 0

Answer:

560 m

Explanation:

The speed of sound in air is approximately:

v ≈ v₀ + 0.6T

where v₀ is the speed of sound at 0°C (273 K) in m/s, and T is the temperature in Celsius.

The speed of sound at 20°C at that altitude is:

v ≈ 327 + 0.6(20)

v ≈ 339 m/s

The sound travels from the hikers to the mountain and back again, so it travels twice the distance.

339 m/s = 2d / 3.3 s

2d = 1118.7 m

d = 559.35 m

Rounding, the mountain is approximately 560 m away.

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olya-2409 [2.1K]

Answer:c ITs C ^w^

Explanation:

4 0

2 years ago

Suppose a straight 1.00-mm-diameter copper wire could just "float" horizontally in air because of the force due to the Earth’s m

insens350 [35]

To solve this problem it is necessary to apply the concepts related to the Force since Newton's second law, as well as the concept of Electromagnetic Force. The relationship of the two equations will allow us to find the magnetic field through the geometric relations of density and volume.

$F_{mag}= BIL$

Where,

B = Magnetic Field

I = Current

L = Length

Note: $F_{mag}$ is a direct adaptation of the vector relation $F=q \times V \times B$

From Newton's second law we know that the relation of Strength and weight is determined as

$F_g = mg$

Where,

m = Mass

g = Gravitational Acceleration

For there to be balance the two forces must be equal therefore

$F_{mag} = F_g$

$BIL = mg$

Our values are given as,

Diameter $(d) = 1.0mm = 1*10^{-3}m$

Radius $(r) = \frac{d}{2} = \frac{1*10^{-3}}{2} = 0.5*10^{-3}m$

Magnetic Field $(B) = 5.0*10^{-5} T$

From the relationship of density another way of expressing mass would be

$\rho = \frac{m}{V} \rightarrow m = \rho V$

At the same time the volume ratio for a cylinder (the shape of the wire) would be

$V = \pi r^2 L \rightarrow L =Length, r= Radius$

Replacing this two expression at our first equation we have that:

$BIL = mg$

$BIL = ( \rho V)g$

$BIL = ( \rho \pi r^2 L)g$

Re-arrange to find I

$I = \frac{( \rho \pi r^2 L)g}{BL}$

$I = \frac{( \rho \pi r^2 )g}{B}$

We have for definition that the Density of copper is $8.9*10^3 Kg/m^3$ , gravity acceleration is $9.8m/s^2$ and the values of magnetic field (B) and the radius were previously given, then:

$I = \frac{( (8.9*10^3 ) \pi (0.5*10^{-3})^2 )(9.8)}{5.0*10^{-5}}$

$I = 1370.05A$

The current is too high to be transported which would make the case not feasible.

8 0

2 years ago

How many significant digits are in the number 0.010?

Soloha48 [4]

There a two significant digits

explanation:
Trailing zeros after a decimal point count if preceded by a non-zero value. Example: 0.01 one significant figure, 0.010 two significant figures, 0.0100 three significant figures.

6 0

2 years ago

Heyyyy help ! What’s the electromagnetic wave that has a wavelength between 1mm and 30cm

LenaWriter [7]

You've got some UHF radio waves at the long end of that range. But most of the range consists of microwaves.

For example: In the US, the "microwave oven" kitchen appliance cooks with radiation at a wavelength of about 12.2 cm .

6 0

2 years ago

In physics 28.97 + 45.876 adds up to what?

myrzilka [38]

$28.97 + 45.876$