A sound with a lot of energy is ___________________

A boxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. The moving boxcar colli

olga2289 [7]

Answer:

2 m/s

Explanation:

Momentum is conserved:

mv = MV

where m is mass of the boxcar, v is its initial velocity, M is the mass of all six box cars, and V is the final velocity.

v = 12 m/s, and M = 6m, so:

m (12 m/s) = 6m V

12 m/s = 6V

V = 2 m/s

6 0

3 years ago

The company where you work has obtained and stored five lasers in a supply room. You have been asked to determine the intensity

VikaD [51]

Answer:

a) I = 5.79 10⁵ W/m² , b) I = 2.58 10² W / m², c) I = 8.03 10³ W / m² , d) I = 5.3 10⁶ W / m², e) I = 9 10¹ W / m² , f) D> A> C> B> E

Explanation:

The intensity is defined as the power per unit area

I = P / A

The area of a circle is

A = π r²

Laser A

Power P = 2.2 W

Diameter d = 2.9 mm = 2.9 10⁻³ m

Let's calculate

Area

A = π d² / 4

A = π (2.2 10⁻³)²/4

A = 3.80 10⁻⁶ m²

Let's calculate the intensity

I = 2.2 / 3.80 10⁻⁶

I = 0.579 10⁶ W / m²

I = 5.79 10⁵ W/m²

Laser B

The electric field is E = 440 V / m

Intensity average is

I = E B / 2 μ₀

The relationship of the fields with the speed of light

E / B = c

The intensity

I = EE / 2 μ₀ c

I = 440² / (2 4π 10⁻⁷ 3 10⁸)

I = 1.936 105/750

I = 2.58 10² W / m²

Laser C

The magnetic field amplitude B = 8.2 10⁻⁶ T

I = c / 2μ₀ B²

I = 3 10⁸/2 4π 10⁻⁷ (8.2 10⁻⁶)²

I = 8.03 10³ W / m²

Part D

Diameter d = 1.8 mm = 1.8 10⁻³ m

The radius is r = d / 2 = 0.9 10⁻³ m

The force is F = 9.0 10⁻⁸ N

The radiation pressure is on a reflective surface is

P = 2S / c

I = S =P c / 2

The definition of pressure is

P = F / A

I = F c / 2 A

I = 9.0 10⁻⁸ 3 10⁸ / (2π (0.9 10⁻³)²)

I = 5.3 10⁶ W / m²

Part E

Average energy density

u = 3.0 10⁻⁷ J / m³

I = S = c u

I = 3 10⁸ 3.0 10⁻⁷

I = 9 10¹ W / m²

Part F

Sort in descending order

The order is

D> A> C> B> E

7 0

3 years ago

You are working at a company that manufactures electrical wire. Gold is the most ductile of all metals: it can be stretched into

devlian [24]

Answer: $R=1.424 M\Omega$

Explanation:

Given

mass of gold $m=1.6 gm$

Length of wire $L=2.2 km$

Resistivity of gold $\rho =2.44\times 10^{-8}$

density of gold $=19.3\times 10^3 kg/m^3$

and $mass=volume\times density$

$1.6\times 10^{-3}=volume\times 19.3\times 10^3$

$volume=8.29\times 10^{-8} m^3$

And $Resistance R=\frac{\rho L}{A}$

also be written as

$R=\frac{\rho L^2}{V}$

where $L=length$

$V=volume$

$\rho =resistivity\ of\ gold$

$R=\frac{2.44\times 10^{-8}\times (2200)^2}{8.29 \times 10^{-8}}$

$R=1.42\times 10^{6} \Omega$

$R=1.424 M\Omega$

5 0

3 years ago

Consider a particle with unit charge q, and mass m, in a constant magnetic field B directed along the positive z–axis. The parti

max2010maxim [7]

Answer:

it must be helical motion in which the charge particle will move uniformly along z axis and simultaneously it will move in circular path in xy plane.

Explanation:

Magnetic field is along z axis while velocity is in x-z plane

so we will have

$F = q(\vec v \times \vec B)$

so here we can say

$F = q(u\hat i + w\hat k) \times (B \hat k)$

so we will have

$F = quB(-\hat j)$

so here the net force on the charge is perpendicular to its x directional velocity along - Y direction

So due to this component of motion it will move along a circle while other component of the motion will remain uniform always

So here it is combination of two parts

1) Uniform circular motion

2) Uniform motion

So we can say that it must be helical motion in which the charge particle will move uniformly along z axis and simultaneously it will move in circular path in xy plane.

4 0

3 years ago

-<br> ZOOLS<br> 6) The mass of a motorcycle is 250 kg. What is?<br> A) Its weight on Earth in Newtons?<br> B) Its weight on the

marishachu [46]

Answer:

Explanation:

Weight is actually a force. A force can change depending on its location. A mass remains constant no matter where it is.

A)

F = m * a

m = 250 kg

a = 9.81 m/s^2

F = 250 * 9.81 = 2452.5 N

B)

The acceleration due to gravity on the moon is roughly 1/6 what it is on earth. You can check its value in your notes.

a = 9.81 + (1/6) = 1.635

m = 250

F = 250 * 1.635

F = 408.75

C)

The mass is the same anywhere in the universe.

250 kg

4 0

3 years ago

A sound with a lot of energy is ____________________ than a sound with less energy.