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3 years ago

If a microwave oven produces electromagnetic waves with a frequency of 2.70 ghz, what is their wavelength?

1 answer:

5 0

Ok this one is pretty straight forward :) This is what we know:

1. 2.7GHz is how many vibrations in 1 second. (2.7 x10^9 Hz)
2. Light always has a constant speed 2.9 x10^8 meters per second.

Therefore to find out the length of one of those vibrations you just divide 2.9 x10^8 by 2.7 x10^9
which looks like this in your calculator:
290000000 / 2700000000
= 0.107m
= 10cm

You might be interested in

Matter can undergo chemical reactions and nuclear reactions, which

asambeis [7]

Answer:

Explanation:

they involve breaking and making chemical bonds

8 0

2 years ago

On a topographic map, contour lines create a group of concentric, closed loops. Which of the following features could this indic

posledela

Answer:

b. Hill top

Explanation:

On a topographic map, the closed circles are meant to represent a hill. So if the contour lines are creating a group of concentric closed loops then it must be an indication of a hill.

3 0

3 years ago

The current theory of the structure of the

IRISSAK [1]

1) The mass of the continent is $3.3\cdot 10^{21} kg$

2) The kinetic energy of the continent is 624 J

3) The speed of the jogger must be 4 m/s

Explanation:

We start by finding the volume of the continent. We have:

$L = 5850 km = 5.85\cdot 10^6 m$ is the side

$t = 35 km = 3.5\cdot 10^4 m$ is the depth

So the volume is

$V=L^2 t = (5.85\cdot 10^6)^2 (3.5\cdot 10^4)=1.20\cdot 10^{18} m^3$

We also know that its density is

$d=2750 kg/m^3$

Therefore, we can find the mass by multiplying volume by density:

$m=dV=(2750)(1.20\cdot 10^{18})=3.3\cdot 10^{21} kg$

The kinetic energy of the continent is given by:

$K=\frac{1}{2}mv^2$

where

$m=3.3\cdot 10^{21} kg$ is its mass

v = 3.2 cm/year is the speed

We have to convert the speed into m/s. We have:

3.2 cm = 0.032 m

$1 year = 1(365)(24)(60)(60)=3.15\cdot 10^7 s$

So, the speed is:

$v=\frac{0.032 m}{3.15 \cdot 10^7 s}=1.02\cdot 10^{-9} m/s$

So, we can now find the kinetic energy:

$K=\frac{1}{2}(1.20\cdot 10^{21})(1.02\cdot 10^{-9})^2=624 J$

Here we have a jogger of mass

m = 78 kg

And the jogger has the same kinetic energy of the continent, so

K = 624 J

The kinetic energy of the jogger is given by

$K=\frac{1}{2}mv^2$

where v is the speed of the jogger.

Solving for v, we find the speed that the jogger must have:

$v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(624)}{78}}=4 m/s$

Learn more about kinetic energy:

brainly.com/question/6536722

#LearnwithBrainly

3 0

3 years ago

A 1200-kg car initially at rest undergoes constant acceleration for 8.8 s, reaching a speed of 10 m/ s. It then collides with a

atroni [7]

Answer:

The final kinetic energy of the two-car system is 60,000 J.

Explanation:

Given;

mass of the car, m = 1200 kg

time of motion, t = 8.8 s

final velocity of the car, v = 10 m/s

Apply the principle of conservation of kinetic energy; the initial kinetic energy is equal final kinetic energy.

$K.E_i = K.E_f\\\\K.E_f = \frac{1}{2}mv^2\\\\K.E_f = \frac{1}{2}(1200)(10)^2\\\\K.E_f = 60,000 \ J$

Therefore, the final kinetic energy of the two-car system is 60,000 J.

4 0

3 years ago

A boy drags a suitcase along the ground with a force of 100 N. If the frictional force opposing the motion of the suitcase is 50

stira [4]

Fortunately, 'force' is a vector. So if you know the strength and direction
of each force, you can easily addum up and find the 'resultant' (net) force.

When we talk in vectors, one newton forward is the negative of
one newton backward. Hold that thought, while I slog through
the complete solution of the problem.

(100 N forward) plus (50 N backward)

= (100 N forward) minus (50 N forward)

= 50 N forward .

That's it.
Is there any part of the solution that's not clear ?

4 0

3 years ago