All categories

3 years ago

Why might we expect venus and earth to be similar?

1 answer:

5 0

They have similar distances from the sun therefore receive similar amounts of solar energy but Venus has no atmosphere to protect it so greater variation in temp.
Both are rock planets unlike those further away from the sun which, because of their distance receive less solor energy are cold, are ice planets

You might be interested in

A unit for measuring frequency is the

jonny [76]

A.) Hertz is the measuring unit for frequency!!
[Your explanation is correct]

Hope this helps!

4 0

3 years ago

7.22 Ignoring reflection at the air–water boundary, if the amplitude of a 1 GHz incident wave in air is 20 V/m at the water surf

Serga [27]

Answer:

z = 0.8 (approx)

Explanation:

given,

Amplitude of 1 GHz incident wave in air = 20 V/m

Water has,

μr = 1

at 1 GHz, r = 80 and σ = 1 S/m.

depth of water when amplitude is down to 1 μV/m

Intrinsic impedance of air = 120 π Ω

Intrinsic impedance of water = $\dfrac{120\pi}{\epsilon_r}$

Using equation to solve the problem

$E(z) = E_0 e^{-\alpha\ z}$

E(z) is the amplitude under water at z depth

E_o is the amplitude of wave on the surface of water

z is the depth under water

$\alpha = \dfrac{\sigma}{2}\sqrt{\dfrac{(120\pi)^2}{\Epsilon_r}}$

$\alpha = \dfrac{1}{2}\sqrt{\dfrac{(120\pi)^2}{80}}$

$\alpha =21.07\ Np/m$

now ,

$1 \times 10^{-6} = 20 e^{-21.07\times z}$

$e^{21.07\times z}= 20\times 10^{6}$

taking ln both side

21.07 x z = 16.81

z = 0.797

z = 0.8 (approx)

5 0

3 years ago

A 26-kg sled is on a snow-covered slope. The coeﬃcients of friction between the sled’s runners and the snow are µs = 0.096 and µ

sweet-ann [11.9K]

Answer:

Explanation:

Given

mass of sled =26 kg

coefficient of static friction $\mu _s=0.096$

coefficient of kinetic friction $\mu _k=0.072$

In order to move sled from rest we need to provide a force greater than static friction which is given by

$f_s=\mu mg=0.096\times 26\times 9.8=24.46 N$

After Moving Sled kinetic friction comes in to play which is less than static friction

$f_k=\mu _kmg=0.072\times 26\times 9.8=18.34 N$

therefore minimum force to keep moving sledge at constant velocity is 18.34 N

3 0

3 years ago

The speed of the wave depends on what?

kolbaska11 [484]

The speed of a mechanical wave depends on the mechanical properties
of the medium through which the wave is traveling.

The speed of an electromagnetic wave depends on the electrical properties
of the medium through which the wave is traveling.

It's pretty well unanimous for choice <em>A</em> .

4 0

3 years ago

An Object, Start from rest w Confront Aiceleration 8m/s2 along a

shutvik [7]

Answer:

A) v = 40 m / s, B) v_average = 20 m / s

Explanation:

For this exercise we will use the kinematics relations

A) the final velocity for t = 5 s and since the body starts from rest its initial velocity is zero

v = vo + a t

v = 0 + 8 5

v = 40 m / s

B) the average velocity can be found with the relation

v_average = vf + vo / 2

v-average = 0+ 40/2

v_average = 20 m / s

6 0

3 years ago