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3 years ago

15

Mr. Brewer drove his car at a speed of 60 miles/hour as he traveled from his house to Troy Prep. What additional information wou

ld you need to determine Mr. Brewer’s velocity?

1 answer:

Lubov Fominskaja [6]3 years ago

4 0

Answer:how long it took him to get there

Explanation:

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X rays of wavelength 0.0169 nm are directed in the positive direction of an x axis onto a target containing loosely bound electr

mamaluj [8]

Answer:

a) 4.04*10^-12m

b) 0.0209nm

c) 0.253MeV

Explanation:

The formula for Compton's scattering is given by:

$\Delta \lambda=\lambda_f-\lambda_i=\frac{h}{m_oc}(1-cos\theta)$

where h is the Planck's constant, m is the mass of the electron and c is the speed of light.

a) by replacing in the formula you obtain the Compton shift:

$\Delta \lambda=\frac{6.62*10^{-34}Js}{(9.1*10^{-31}kg)(3*10^8m/s)}(1-cos132\°)=4.04*10^{-12}m$

b) The change in photon energy is given by:

$\Delta E=E_f-E_i=h\frac{c}{\lambda_f}-h\frac{c}{\lambda_i}=hc(\frac{1}{\lambda_f}-\frac{1}{\lambda_i})\\\\\lambda_f=4.04*10^{-12}m +\lambda_i=4.04*10^{-12}m+(0.0169*10^{-9}m)=2.09*10^{-11}m=0.0209nm$

c) The electron Compton wavelength is 2.43 × 10-12 m. Hence you can use the Broglie's relation to compute the momentum of the electron and then the kinetic energy.

$P=\frac{h}{\lambda_e}=\frac{6.62*10^{-34}Js}{2.43*10^{-12}m}=2.72*10^{-22}kgm\\$

$E_e=\frac{p^2}{2m_e}=\frac{(2.72*10^{-22}kgm)^2}{2(9.1*10^{-31}kg)}=4.06*10^{-14}J\\\\1J=6.242*10^{18}eV\\\\E_e=4.06*10^{-14}(6.242*10^{18}eV)=0.253MeV$

5 0

3 years ago

What type of lever has the fulcrum between the resistance arm and the effort arm?

crimeas [40]

I’m not really sure but I think it’s D type 1 lever

4 0

3 years ago

Two cylindrical resistors are made from the same material. The shorter one has length L, diameter D, and resistance R1. The long

nordsb [41]

Answer:

the resistance of the longer one is twice as big as the resistance of the shorter one.

Explanation:

Given that :

For the shorter cylindrical resistor

Length = L

Diameter = D

Resistance = R1

For the longer cylindrical resistor

Length = 8L

Diameter = 4D

Resistance = R2

So;

We all know that the resistance of a given material can be determined by using the formula :

$R = \dfrac{\rho L }{A}$

where;

A = πr²

$R = \dfrac{\rho L }{\pi r ^2}$

For the shorter cylindrical resistor ; we have:

$R = \dfrac{\rho L }{\pi r ^2}$

since 2 r = D

$R = \dfrac{\rho L }{\pi (\frac{2}{2 \ r}) ^2}$

$R = \dfrac{ 4 \rho L }{\pi \ D ^2}$

For the longer cylindrical resistor ; we have:

$R = \dfrac{\rho L }{\pi r ^2}$

since 2 r = D

$R = \dfrac{ \rho (8 ) L }{\pi (\frac{2}{2 \ r}) ^2}$

$R = \dfrac{32\rho L }{\pi \ (4 D) ^2}$

$R = \dfrac{2\rho L }{\pi \ (D) ^2}$

Sp;we can equate the shorter cylindrical resistor to the longer cylindrical resistor as shown below :

$\dfrac{R_s}{R_L} = \dfrac{ \dfrac{ 4 \rho L }{\pi \ D ^2}}{ \dfrac{2\rho L }{\pi \ (D) ^2}}$

$\dfrac{R_s}{R_L} ={ \dfrac{ 4 \rho L }{\pi \ D ^2}}* { \dfrac {\pi \ (D) ^2} {2\rho L}}$

$\dfrac{R_s}{R_L} =2$

${R_s}=2{R_L}$

Thus; the resistance of the longer one is twice as big as the resistance of the shorter one.

7 0

3 years ago

erik [133]

Answer:

Sound waves in liquids and gases involve alternating compression and rarefaction of material along a line defining the direction of propagation of the wave. These waves are known as longitudinal waves, and of course exist only in a medium that can be compressed and rarefied. In solids, sound energy also produces longitudinal waves, but it can also produce transverse waves, in which compression and rarefaction occurs perpendicular to the direction of propagation. These two waves propagate at different speeds, a phenomenon that is most noticeable in earthquakes. The first wave gives notice that the quake is coming, the second one does the damage. The time between the two tells you how far away the epicenter is. In water there is another kind of wave, called a gravity wave, the kind you see at the beach. All of these wave require a medium. There is no sound in a vacuum.

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3 years ago

Expository essay "Climate change in Fiji"

ikadub [295]

Answer: Climate change poses to the tourism development in Fiji islands. It shows the adverse effects of the changing climate and the dangers pose by the tourism activities and also pose a major hazard for the local people in the region. It also deals with the dangerous carbon emissions and CO2 effect on the landscape, food, water, energy.

The pacific is the world`s largest ocean with a surface area of 175 million sq km and constitutes for 40% of the planet`s waters. Located in the tropical latitudes, it covers more than half the globe`s circumference. Temperature of the surface water in the western tropical regions is always more than 28 ÌŠC over a depth of several hundred meters. This makes up the world`s storage of thermal energy for exchange with atmosphere. Here the interaction between atmosphere and ocean is most extreme and influences the climate not only regionally but planet-wide. The nations of the pacific are obscured human settlements absorbed in this vast fluid universe. The ocean is the most important factor controlling the environment and life.

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3 years ago