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2 years ago

Explain why xrays are used to take images of inside the body but UV isnt

Physics

1 answer:

Sidana [21]2 years ago

6 0

Answer:

X-rays go all the way through the body, but ultraviolet rays do not.

Explanation:

An x-ray will show inside the body, but uv light isn't strong enough to go all the way through the body.

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Estimate the wavelength corresponding to maximum emission from each of the following surfaces: the sun, a tungsten filament at 2

igomit [66]

Answer

Applying Wein's displacement

$\lamda_{max}\ T = 2898 \mu_mK$

1) for sun T = 5800 K

$\lambda_{max} = \dfrac{2898}{5800}$

$\lambda_{max} = 0.5 \mu_m$

2) for tungsten T = 2500 K

$\lambda_{max} = \dfrac{2898}{2500}$

$\lambda_{max} = 1.16 \mu_m$

3) for heated metal T = 1500 K

$\lambda_{max} = \dfrac{2898}{1500}$

$\lambda_{max} = 1.93 \mu_m$

4) for human skin T = 305 K

$\lambda_{max} = \dfrac{2898}{305}$

$\lambda_{max} = 9.50 \mu_m$

5) for cryogenically cooled metal T = 60 K

$\lambda_{max} = \dfrac{2898}{60}$

$\lambda_{max} = 48.3 \mu_m$

range of different spectrum

UV ----0.01-0.4

visible----0.4-0.7

infrared------0.7-100

for sun T = 5800

λ 0.01 0.4 0.7 100

λT 58 2320 4060 5.8 x 10⁵

F 0 0.125 0.491 1

fractions

for UV = 0.125

for visible = 0.441-0.125 = 0.366

for infrared = 1 -0.491 = 0.509

8 0

3 years ago

A cannon fires a shell straight upward; 2.3 s after it is launched, the shell is moving upward with a speed of 17 m/s. Assuming

PtichkaEL [24]

Answer:

The speed of the shell at launch and 5.4 s after the launch is 13.38 m/s it is moving towards the Earth.

Explanation:

Let u is the initial speed of the launch. Using first equation of motion as :

$u=v-at$

a=-g

$u=v+gt\\\\u=17+9.8\times 2.3\\\\u=39.54\ m/s$

The velocity of the shell at launch and 5.4 s after the launch is given by :

$v=u-gt\\\\v=39.54-9.8\times 5.4\\\\v=-13.38\ m/s$

So, the speed of the shell at launch and 5.4 s after the launch is 13.38 m/s it is moving towards the Earth.

6 0

3 years ago

Someone please help @countrygirllove1

natali 33 [55]

The layers form from sand dunes

6 0

3 years ago

Which would hit the ground first if dropped from the same height in a vacuum—a feather or a metal bolt?

vovikov84 [41]

They hit the ground at the same time

4 0

2 years ago

A gas contained within a piston-cylinder assembly undergoes two processes, A and B, between the same end states, 1 and 2, where

Sidana [21]

Answer:

a) 90 kJ

b) 230.26 kJ

Explanation:

The pressure at the first point $P_{1}$ = 10 bar —> 10 x 102 = 1020 kPa

The volume at the first point $V_{1}$ = 0.1 m^3

The pressure at the second point $P_{2}$ = 1 bar —> 1 x 102 = 102 kPa

The volume at the second point $V_{2}$ = 1 m^3

Process A.

constant volume V = C from point (1) to P = 10 bar.

Constant pressure P = C to the point (2).

Process B.

The relation of the process is PV = C

Required

For process A & B

(a) Sketch the process on P-V coordinates

(b) Evaluate the work W in kJ.

Assumption

Quasi-equilibrium process

Kinetic and potential effect can be ignored.

Solution

For process A.

V=C

There is no change in volume then

$W_{a(1)}= 0\\P=10^{2}$

The work is defined by

$W_{a(2)}=\int\limits^V_V {P} \, dV$

$W_{A(2)} =$ ║ $10^{2}$ V║limit 1--0.1

$W_{A(2)} =$ 90 kJ

Process B

PV=C

By substituting with point (1) C = 10^2 x 1= 10^2

The work is defined by

$W_{b}=\int\limits^V_V {P} \, dV\\P=10^{2} V^{-1}\\ W_{b}=\int\limits^V_V {10^{2} V^{-1}} \, dV\\\\$

$W_{A(2)} =$ ║ $10^{2}$ ln(V)║limit 1--0.1

=230.26 kJ

3 0

3 years ago