If you are asked to determine an object’s speed, what information must you have?

Which statement accurately describes current electricity?

Colt1911 [192]

Answer:

C. It is caused by flowing negatively charged particles.

Explanation:

Current electricity is caused by flowing negatively charged particles. The negatively charged particles that are responsible for the flow of electricity are called electrons.

The force is equal at all points in the field as the field lines are parallel in a uniform field. So, negatively charged particles will move in the opposite direction to the current.

Hence, the correct answer is "C. It is caused by flowing negatively charged particles."

8 0

3 years ago

A LASIK vision-correction system uses a laser that emits 10-ns-long pulses of light, each with 3.0 mJ of energy. The laser beam

lyudmila [28]

P = energy/t = 0.0025/1E-8 = 250000 W
I(ave) = P/A = 250000/(pi*0.425E-3^2) = 4.4056732E11 W/m^2
I(peak) = 2I(ave) = 8.8113463E11 W/m^2
Electric field E = sqrt(I(peak)*Z0) = 1.8219499E7 V/m, where
free-space impedance Z0 = sqrt(µ0/e0) = 376.73031 ohms

7 0

3 years ago

What happens to the force of gravity between two masses if one mass is decreased?

Andrews [41]

B. It stays the same

7 0

3 years ago

Read 2 more answers

the gravitational force between two objects is 1600 and what will be the gravitational force between the objects if the distance

Xelga [282]

I believe this is what you have to do:

The force between a mass M and a point mass m is represented by

$F = G\frac{Mm}{r^{2} }$

So lets compare it to the original force before it doubles, it would just be the exact formula so lets call that F₁

So F₁ = G(Mm/r^2)

Now the distance has doubled so lets account for this in F₂:

F₂ = G(Mm/(2r)^2)

Now square the 2 that gives you four and we can pull that out in front to give

F₂ = $\frac{1}{4}$ G(Mm/r^2)

Now we can replace G(Mm/r^2) with F₁ as that is the value of the force before alterations

now we see that:

F₂ = $\frac{1}{4}$ F₁

So the second force will be 0.25 (1/4) x 1600 or 400 N.

6 0

3 years ago

What are radioactive isotopes?

melisa1 [442]

Answer:

Radioactive isotope , also called radioisotope,

radionuclide, or radioactive nuclide, any of

several species of the same chemical element

with different masses whose nuclei are unstable

and dissipate excess energy by spontaneously

emitting radiation in the form of alpha , beta , and

gamma rays .

A brief treatment of radioactive isotopes follows.

For full treatment, see isotope: Radioactive

Radioactiveisotopes.

Every chemical element has one or more

radioactive isotopes. For example, hydrogen, the

lightest element, has three isotopes with mass

numbers 1, 2, and 3. Only hydrogen-3 (tritium ),

however, is a radioactive isotope , the other two

being stable. More than 1,000 radioactive

isotopes of the various elements are known.

Approximately 50 of these are found in nature;

the rest are produced artificially as the direct

products of nuclear reactions or indirectly as the

radioactive descendants of these products.

Radioactive isotopes have many useful

applications. In medicine , for example, cobalt -60

is extensively employed as a radiation source to

arrest the development of cancer. Other

radioactive isotopes are used as tracers for

diagnostic purposes as well as in research on

metabolic processes. When a radioactive isotope

is added in small amounts to comparatively large

quantities of the stable element, it behaves

exactly the same as the ordinary isotope

chemically; it can, however, be traced with a

Geiger counter or other detection device.

Iodine -131 has proved effective in treating

hyperthyroidism. Another medically important

radioactive isotope is carbon-14, which is used in

a breath test to detect the ulcer-causing bacteria

Heliobacter pylori .

Explanation:

#learnwithbrainly

8 0

3 years ago