Two thermometers are calibrated, one in de

Carbon-14 has a half-life of 5,700 years. How long will it take for 6.25% of the Carbon-14 to be remaining?

kupik [55]

Half life is 5700 years,that is 50%.

6.25% means 1/16 of the life is left.

T^1/16 =T^1/2*4.

5700 × 4 =22800 years

7 0

3 years ago

A student asks the following question:

MariettaO [177]

Answer:

Natalie says that all things with mass have a gravitational field, but the force is very weak and cannot be perceived around small objects.

Explanation:

The force due to gravity is proportional to the mass of the object and inversely proportional to the square of the distance between objects. The Earth is so massive that the force due to its gravity is much greater than the force between objects on the counter.

If there were no friction, the objects might move toward each other, depending on what other masses were near them tending to cause them to move in other directions.

Natalie's explanation is about the best.

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<em>Additional comment</em>

The universal gravitational constant was determined by Henry Cavendish in the late 18th century using lead balls weighing 1.6 pounds and 348 pounds. His experiment was enclosed in a large wooden box to minimize outside effects. While these masses are somewhat greater than those of a glue bottle and stapler, the experiment shows the force of gravity between "small" objects <em>can</em> be measured.

8 0

3 years ago

The downlink frequency is lower than the uplink frequency. True or False

miv72 [106K]

Answer:

I think it is true

Explanation:

4 0

3 years ago

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In si units, the electric field in an electromagnetic wave is described by ey = 104 sin(1.40 107x − ωt). (a) find the amplitude

melamori03 [73]

Answers:
(a) $B_o = 0.3466$ μT
(b) $\lambda = 0.4488$ μm
(c) f = $6.68 * 10^{14}Hz$

Explanation:
Given electric field(in y direction) equation:
$E_y = 104sin(1.40 * 10^7 x -\omega t)$

(a) The amplitude of electric field is $E_o = 104$ . Hence

The amplitude of magnetic field oscillations is $B_o = \frac{E_o}{c}$
Where c = speed of light

Therefore,
$B_o = \frac{104}{3*10^8} = 0.3466$ μT (Where T is in seconds--signifies the oscillations)

(b) To find the wavelength use:
$\frac{2 \pi }{\lambda} = 1.40 * 10^7$
$\lambda = \frac{2 \pi}{1.40} * 10^{-7}$
$\lambda = 0.4488$ μm

(c) Since c = fλ
=> f = c/λ

Now plug-in the values
f = (3*10^8)/(0.4488*10^-6)
f = $6.68 * 10^{14}Hz$

6 0

3 years ago

Which of the following statements about floating objects is always true? a. The object’s density is greater than the density of

Yuki888 [10]

It should be C. If the object is denser than the fluid, it will sink. If it isn't, it will float

6 0

3 years ago

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