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3 years ago

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Sally is concerned about the X-ray images her dentist plans to take of her teeth. She has read that X-rays can cause tissue effe

cts, such as skin reddening and hair loss. Which statement would best inform Sally of the level of risk

1 answer:

taurus [48]3 years ago

6 0

Answer:

The dentist uses X-ray radiography, which takes too short a time to cause those problems.

Explanation:

I took the test on Edg

You might be interested in

Steel is made of atoms of iron and carbon. Would iron and carbon form metallic bonds? Explain your answer choice.

Hatshy [7]

Sample Response: "No, steel and carbon would not form metallic bonds because metallic bonds only form between metals. Iron is a metal, but carbon is not."

7 0

2 years ago

Read 2 more answers

1. 1500j of work was done to move a box 20m. What force was applied to the box ?

Fantom [35]

Answer:

1. 75N

2. 67,983 J (=67.98 kJ)

Explanation:

1. Work = Force x Distance

we are given that Work = 1,500J and Distance = 20m

hence,

Work = Force x Distance

1,500 = Force x 20

Force = 1,500 ÷ 20 = 75N

2. Potential Energy, PE = mass x gravity x change in height

we are given that mass = 165 kg and change in height = 42m

assuming that gravity, g = 9.81 m/s²

Potential Energy, PE = mass x gravity x change in height

Potential Energy, PE = 165 x 9.81 x 42 = 67,983 J (=67.98 kJ)

4 0

3 years ago

A 3.00N rock is thrown vertically into the air from the ground. At h=15.0m, v=25m/s upward. Use the work-energy theorem to find

butalik [34]

Answer:

so initial speed of the rock is 30.32 m/s

correct answer is b. 30.3 m/s

Explanation:

given data

h = 15.0m

v = 25m/s

weight of the rock m = 3.00N

solution

we use here work-energy theorem that is express as here

work = change in the kinetic energy ..............................1

so it can be written as

work = force × distance ...................2

and

KE is express as

K.E = 0.5 × m × v²

and it can be written as

F × d = 0.5 × m × (vf)² - (vi)² ......................3

here

m is mass and vi and vf is initial and final velocity

F = mg = m (-9.8) , d = 15 m and v{f} = 25 m/s

so put value in equation 3 we get

m (-9.8) × 15 = 0.5 × m × (25)² - (vi)²

solve it we get

(vi)² = 919

vi = 30.32 m/s

so initial speed of the rock is 30.32 m/s

5 0

3 years ago

If a spring is stretched 4m from its starting length when 20n of force is applied, then how much work (in joules) is done by the

lys-0071 [83]

ANSWER:

250 J

STEP-BY-STEP EXPLANATION:

F = 20N is required to stretch the spring by 4 meters

We know that the force is equal to:

$F=k\cdot x$

We solve for k (spring constant):

$k=\frac{F}{x}=\frac{20}{4}=5\text{ N/m}$

The work done in stretching the spring is given by the following equation (in this case the stretch is 10 meters:

$\begin{gathered} W=\frac{1}{2}k\cdot x^2 \\ \text{ Replacing} \\ W=\frac{1}{2}\cdot5\cdot10^2 \\ W=250\text{ J} \end{gathered}$

The work required is 250 joules.

5 0

1 year ago

Two small plastic spheres each have a mass of 1.1 g and a charge of -50.0 nC . They are placed 2.1 cm apart (center to center).

Solnce55 [7]

Answer:

Part a)

F = 0.051 N

Part b)

Both spheres will follow Newton's III law of action reaction force so both sphere will have same force of equal magnitude.

Explanation:

Part a)

Electrostatic force between two charged spherical balls is given as

$F = \frac{kq_1q_2}{r^2}$

here we will have

$q_1 = q_2 = 50 nC$

here the distance between the center of two balls is given as

$r = 2.1 cm = 0.021 m$

now we will have

$F = \frac{(9\times 10^9)(50 \times 10^{-9})(50 \times 10^{-9})}{0.021^2}$

$F = 0.051 N$

Part b)

Both spheres will follow Newton's III law of action reaction force so both sphere will have same force of equal magnitude.

3 0

2 years ago