Ask question

Ask question

All categories

4 years ago

10

X-rays can be dangerous. Please select the best answer from the choices provided T F

2 answers:

Mrrafil [7]4 years ago

8 0

Yes x-rays can be dangerous because if too much of it radiates it can be harmful over the course of years like Marie Curie

Setler79 [48]4 years ago

4 0

It is true. They can be dangerous.

You might be interested in

A parachutist relies on air resistance (mainly on her parachute) to decrease her downward velocity. She and her parachute have a

wlad13 [49]

The resultant force will be equal to difference of her downward force, her weight, and the upward force, the air resistance.
Fnet = 657 - 51.1 x 9.81
= 149.7 N
F = ma
a = F / m
a = 149.7/51.1
a = 2.93 m/s²

3 0

4 years ago

Earth has a magnetic dipole moment of 8.0 × 1022 J/T. (a) What current would have to be produced in a single turn of wire extend

Bogdan [553]

Answer:

a

The current that would be produced is $I = 6.26 *10 ^8 A$

b

Yes this arrangement can be used to cancel out earths magnetic field at points well above the Earth's surface.This is because this current loop acts as a magnetic dipole for point above the earth surface

c

No this arrangement can not be used to cancel out earths magnetic field at points on the Earth's surface .this because on the earth surface it shifts from its behavior as a magnetic dipole

Explanation:

From the question we are told that

The magnetic moment of earth is $M = 8.0*10 ^{22} J/T$

The radius of earth generally has a value of $R = 6378 *10^3 m$

Magnetic moment is mathematically given as

$M = IA$

A is the area of the of the earth(assumption that the earth is circular ) and this evaluated as

$A = \pi R^2$

Now making $I$ the subject in the above formula

$I = \frac{M}{A}$

$= \frac{M}{\pi R^2}$

$= \frac{8.0^10^{22}}{\pi (6378 *10^{3})^2}$

$= 6.26 *10^8 A$

5 0

3 years ago

A sound wave with a frequency of 300 hertz is traveling through a medium at a speed of 320 meters/second. What is its wavelength

Sonja [21]

Using the relationship: speed=wavelength·frequency you get:
wavelength=320/300=1.06 m

3 0

4 years ago

Read 2 more answers

If the specific surface energy for magnesium oxide is 1.0 J/m2 and its modulus of elasticity is (225 GPa), compute the critical

alexdok [17]

Answer:

The critical stress required for the propagation of an initial crack $\sigma_{c}$ = 21.84 M pa

Explanation:

Given data

Modulus of elasticity E = 225 × $10^{9}$ $\frac{N}{m^{2} }$

Specific surface energy for magnesium oxide is $\gamma_{s}$ = 1 $\frac{J}{m^{2} }$

Crack length (a) = 0.3 mm = 0.0003 m

Critical stress is given by $\sigma_{c}^{2} }$ = $\frac{2 E \gamma}{\pi a}$ -------- (1)

⇒ 2 E $\gamma_{s}$ = 2 × 225 × $10^{9}$ × 1 = 450 × $10^{9}$

⇒ $\pi$ a = 3.14 × 0.0003 = 0.000942

⇒ Put these values in equation 1 we get

⇒ $\sigma_{c}^{2} }$ = $\frac{450 }{0.000942} 10^{9}$

⇒ $\sigma_{c}^{2} }$ = 4.77 × $10^{14}$

⇒ $\sigma_{c}$ = 2.184 × $10^{7}$ $\frac{N}{m^{2} }$

⇒ $\sigma_{c}$ = 21.84 $\frac{N}{mm^{2} }$

⇒ $\sigma_{c}$ = 21.84 M pa

This is the critical stress required for the propagation of an initial crack.

4 0

3 years ago

If the period of a wave is 9.2 s, what is its frequency (in Hz)?

gogolik [260]

<u>The period of the function is the inverse of the frequency</u>:

⇒ (<em>in other words)</em> $period = \frac{1}{frequency}$

<u>Since the period is 9.2s</u>:

$Frequency = \frac{1}{period}=\frac{1}{9.2} =0.11_.Hz$

<u>Answer: 0.11 Hz</u>

<u></u>

Hope that helps!

8 0

2 years ago