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3 years ago

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

2 answers:

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]3 years ago

4 0

It is true. They can be dangerous.

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How can I covert these 2,34 meters in decimeters

zysi [14]

Answer:

If you meant 2.34, 2.34 meters = 23.4 decimeters.

Formula: multiply the value in meters by the conversion factor '10'.

So, 2.34 meters = 2.34 × 10 = 23.4 decimeters.

Hope that helps. x

4 0

2 years ago

Read 2 more answers

The voltage in the lines that carry electric power to homes is typically 2000 V. What is the required ratio of the loops in the

mariarad [96]

Answer:

yurrrrr 221n54

Explanation:

yurrrrrrrrrrrrrrrrrrrrrr

6 0

3 years ago

Read 2 more answers

HELP ASAP TIMED TEST

balu736 [363]

Answer:

Correct choice: b 4H

Explanation:

Conservation of the mechanical energy

The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):

E = U + K

The GPE is calculated as:

U = mgh

And the kinetic energy is:

$\displaystyle K=\frac{1}{2}mv^2$

Where:

m = mass of the object

g = gravitational acceleration

h = height of the object

v = speed at which the object moves

When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:

$U_1 = mgH$

When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:

$\displaystyle U_2=\frac{1}{2}mv^2$

Since the energy is conserved, U1=U2

$\displaystyle mgH=\frac{1}{2}mv^2 \qquad\qquad [1]$

For the speed to be double, we need to drop the snowball from a height H', and:

$\displaystyle mgH'=\frac{1}{2}m(2v)^2$

Operating:

$\displaystyle mgH'=4\frac{1}{2}m(v)^2 \qquad\qquad [2]$

Dividing [2] by [1]

$\displaystyle \frac{mgH'}{mgH}=\frac{4\frac{1}{2}m(v)^2}{\frac{1}{2}m(v)^2}$

Simplifying:

$\displaystyle \frac{H'}{H}=4$

Thus:

H' = 4H

Correct choice: b 4H

4 0

3 years ago

A hockey puck is struck so that it slides at a constant speed and strikes the far side of the rink, 58.2 m away. The shooter hea

DENIUS [597]

Answer:

$v = 33.66 m/s$

Explanation:

Let hockey puck is moving at constant speed v

so here we have

$d = vt$

so time taken by the puck to strike the wall is given as

$t = \frac{58.2}{v}$

now time taken by sound to come back at the position of shooter is given as

$t_2 = \frac{58.2}{340}$

$t_2 = 0.17s$

so we know that total time is 1.9 s

$1.9 = t + t_2$

$1.9 = t + 0.17$

$1.9 - 0.17 = t$

$t = 1.73 s$

now we have

$1.73 = \frac{58.2}{v}$

$v = 33.66 m/s$

7 0

3 years ago

How did ALS impact Stephen Hawking?

olga nikolaevna [1]

Answer:

Professor Hawking had just turned 21 when he was diagnosed with a very rare slow-progressing form of ALS, a form of motor neurone disease (MND). He was at the end of his time at Oxford when he started to notice early signs of his disease. He was getting more clumsy and fell over several times without knowing why.

Explanation:

none

6 0

3 years ago