Anything that moves up and down or back and forth in a rhythmic way is vibrating true false

The double inclined plane supports two blocks A and B, each having a weight of 10 lb. If the coefficient of kinetic friction bet

Vladimir79 [104]

Answer:

Explanation:

Left block is on surface with higher inclination so it will go down . If T be tension

For motion of block A ,

net force = mgsin60 - (T + mg cos 60 x μ ) , μ is coefficient of friction .

ma = mgsin60 - T - mg cos 60 x .1

10a = 277.13 - T - 16

= 261.13 - T

T = 261.13 - 10a

For motion of block B

T - mg sin30 - mgcos30 x μ = ma

T- 160 - 27.71 = 10 a

261.13 - 10a - 160 - 27.71 = 10a

73.42 = 20a

a = 3.67 ft / s²

common acceleration = 3.67 ft / s²

8 0

4 years ago

a school bus takes 0.50 hours to reach the school from your home. if the average speed of the bus is 20km/h, what is displacemen

Kazeer [188]

Answer:

10 km

Explanation:

.5 hr * 20 km/hr = 10 km

8 0

1 year ago

Which observation is the best evidence that some colors of visible light are

Effectus [21]

Answer:

id say D

Explanation:

because its the only answer that has to do with colors and visable light

but A and B also have to do with eachother so i feel like it could be with one of those but it def isnt C

I am sorry if i am wrong, let me know tho!

8 0

3 years ago

Read 2 more answers

A 300 MHz electromagnetic wave in air (medium 1) is normally incident on the planar boundary of a lossless dielectric medium wit

Masja [62]

Answer:

Wavelength of the incident wave in air = 1 m

Wavelength of the incident wave in medium 2 = 0.33 m

Intrinsic impedance of media 1 = 377 ohms

Intrinsic impedance of media 2 = 125.68 ohms

Check the explanation section for a better understanding

Explanation:

a) Wavelength of the incident wave in air

The frequency of the electromagnetic wave in air, f = 300 MHz = 3 * 10⁸ Hz

Speed of light in air, c = 3 * 10⁸ Hz

Wavelength of the incident wave in air:

$\lambda_{air} = \frac{c}{f} \\\lambda_{air} = \frac{3 * 10^{8} }{3 * 10^{8}} \\\lambda_{air} = 1 m$

Wavelength of the incident wave in medium 2

The refractive index of air in the lossless dielectric medium:

$n = \sqrt{\epsilon_{r} } \\n = \sqrt{9 }\\n =3$

$\lambda_{2} = \frac{c}{nf}\\\lambda_{2} = \frac{3 * 10^{6} }{3 * 3 * 10^{6}}\\\lambda_{2} = 1/3\\\lambda_{2} = 0.33 m$

b) Intrinsic impedances of media 1 and media 2

The intrinsic impedance of media 1 is given as:

$n_1 = \sqrt{\frac{\mu_0}{\epsilon_{0} } }$

Permeability of free space, $\mu_{0} = 4 \pi * 10^{-7} H/m$

Permittivity for air, $\epsilon_{0} = 8.84 * 10^{-12} F/m$

$n_1 = \sqrt{\frac{4\pi * 10^{-7} }{8.84 * 10^{-12} } }$

$n_1 = 377 \Omega$

The intrinsic impedance of media 2 is given as:

$n_2 = \sqrt{\frac{\mu_r \mu_0}{\epsilon_r \epsilon_{0} } }$

Permeability of free space, $\mu_{0} = 4 \pi * 10^{-7} H/m$

Permittivity for air, $\epsilon_{0} = 8.84 * 10^{-12} F/m$

ϵr = 9

$n_2 = \sqrt{\frac{4\pi * 10^{-7} *1 }{8.84 * 10^{-12} *9 } }$

$n_2 = 125.68 \Omega$

c) The reflection coefficient,r and the transmission coefficient,t at the boundary.

Reflection coefficient, $r = \frac{n - n_{0} }{n + n_{0} }$

You didn't put the refractive index at the boundary in the question, you can substitute it into the formula above to find it.

$r = \frac{3 - n_{0} }{3 + n_{0} }$

Transmission coefficient at the boundary, t = r -1

d) The amplitude of the incident electric field is $E_{0} = 10 V/m$

Maximum amplitudes in the total field is given by:

$E = tE_{0}$ and $E = r E_{0}$

E = 10r, E = 10t

3 0

3 years ago

Which is the correct option?

iris [78.8K]

Answer:

B

Explanation:

Bescouse a neutron is a robot and a fission is not

7 0

4 years ago