EM Waves have crests, troughs, and wavelengths True or false?

How much water is stored in polar ice caps glaciers and permanent snow

antoniya [11.8K]

Answer:

1.7% is stored in the polar icecaps, glaciers, and permanent snow

Explanation:

70% of the Earth's surface is covered with water; However, only a small percentage, 0.025%, is suitable for human consumption. A limited resource whose demand, according to the forecasts of the Organization for Economic Cooperation and Development (OECD), will skyrocket up to 55% globally between 2000 and 2050.

In the attached infographic we observe that the total volume of water on Earth is 1,386 million cubic kilometers, of which 1.7% is forming polar ice, cap glaciers and permanent snow. 1,338 million cubic kilometers of that water is in seas and oceans, that is, 96.5% is in seas and oceans, that is, it is salt water that cannot be drunk.

Only 3.5% of the Earth's water is fresh, but of this percentage, only 1% of the Earth's fresh water flows through the river basins in the form of streams and rivers.

8 0

3 years ago

A force of 45 N is applied tangentially to the rim of a solid disk of radius 0.12 m. The disk rotates about an axis through its

bearhunter [10]

Answer:

Mass of the disk will be 2.976 kg

Explanation:

We have given force F = 45 N

Radius of the disk r = 0.12 m

Angular acceleration $\alpha =140rad/sec^2$

We know that torque $\tau =I\alpha$

And $\tau =Fr$

So $Fr=I\alpha$ , here I is moment of inertia

So $50\times 0.12=I\times 140$

$I=0.0428kgm^2$

We know that moment of inertia $I=\frac{1}{2}mr^2$

So $0.0428=\frac{1}{2}\times m\times 0.12^2$

m = 2.976 kg

6 0

3 years ago

How much force is required to accelerate a 2 kg mass at 3 m/s2

swat32

Force = (mass) x (acceleration) Newton's second law of motion.

Force = (2 kg) x (3 m/s²) = 6 newtons.

3 0

4 years ago

Imagine an alternate universe where the value of the Planck constant is . In that universe, which of the following objects would

HACTEHA [7]

Question: The planck constant was not given. In this calculation, planck constant of 6.62607*10^-9 Js is used for the calculation.

Answer:

(a) A virus -------------Classical

(b) A buckyball -----Classical

(c) A mosquito ------ Quantum

(d) A turtle ------------Quantum

Explanation:

Calculating the wavelength using the formula;

λ= h/(mv)

where

λ= Wavelength

h = Planck Constant = 6.62607*10^-9 Js

m = mass in kg

v = velocity in m/s

Virus size = 280. nm = 2.80*10⁻⁷ m

a)

A Virus:

m = 9.4 x 10-17 g 9.4*10⁻²⁰ kg

v = 0.50 µm/s = 5 *10⁻⁷ m/s

h = 6.62607*10^-9 Js

Virus size = 280 nm = 2.80*10⁻⁷ m

Substituting into the formula; we have

λ= h/(mv)

λ= 6.62607*10^-9/ (9.4*10⁻²⁰* 5 *10⁻⁷)

= 6.62607*10^-9/4.7*10^-26

= 1.4*10^17 m

Classical : Wavelength is bigger than it's size

(b)

A buckyball

m = 1.2 x 10-21 g = 1.2 *10⁻²⁴ kg

V = 37 m/s

Size = 0.7 nm = 7*10⁻¹⁰ m

Substituting into the formula, we have

λ= h/(mv)

λ= 6.62607*10^-9/ ( 1.2 *10⁻²⁴* 37)

= 6.62607*10^-9/4.44*10^-23

= 1.49 *10^14 m

Classical : Wavelength is bigger than it's size

(c)

A mosquito

Mass = 1.0 mg = 1*10⁻⁶ kg

v = 1.1 m/s

Size = 6.3 mm = 6.3*10⁻³ m

Substituting into the formula, we have

λ= h/(mv)

λ= 6.62607*10^-9/ ( 1*10⁻⁶* 1.1)

= 6.62607*10^-9/1.1*10^-6

= 6.02*10^-3 m

Quantum Approach: The wavelength and the size are comparable

(d)

A turtle

Mass = 710. g = 0.71 kg

Size = 22. cm = 0.22 m

V = 2.8 cm/s. = 0.028 m/s

Substituting into the formula, we have

λ= h/(mv)

λ= 6.62607*10^-9/ ( 0.71* 0.028)

= 6.62607*10^-9/0.01988

= 3.33*10^-7 m

Quantum Approach: The wavelength and the size are comparable

8 0

3 years ago

Select the correct answer

Rasek [7]

Answer:

I would say the net force acting on the car is in the opposite direction of the car's motion is correct

5 0

3 years ago

Read 2 more answers