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3 years ago

Which statement is completely accurate?

Physics

2 answers:

zepelin [54]3 years ago

7 0

The correct answer is D. Atoms of the same element can have different number of neutrons.

Rainbow [258]3 years ago

3 0

Elements are identified by their atoms' number of protons. So different neutron amounts will not affect the identity of the atom.

For example, a Hydrogen atom has only 1 proton and no neutrons (H¹). If you add a neutron and make it 1 proton and 1 neutron (H²), it will still be a Hydrogen but just a different isotope which is called Deuterium.

Thus, the answer is D

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Which statement describes an AC generator?

gregori [183]

AC (Alternating Current) generator is a device that produces an electromotive force.This generator produces alternating current. Alternating current is electric current that changes its direction many times a second, at regular intervals. This is the type of current with which customers are supplied in the energy distribution network.

6 0

4 years ago

Read 2 more answers

A 1.2kg stone is tied to a string and swung in a vertical circle with a radius of 0.75m. The string can withstand a tension of 4

san4es73 [151]

Hello!

We can begin by summing the forces acting on the stone when it is at the bottom of its trajectory.

Refer to the free-body diagram in the image below for clarification.

We have the force of tension (produced by the string) and the force of gravity acting in opposite directions, so:
$\Sigma F = T - F_g$

The net force is equivalent to the centripetal force experienced by the stone. Recall the equation for centripetal force for uniform circular motion:
$F_c = \frac{mv^2}{r}$

m = mass of object (1.2 kg)
v = velocity of object (? m/s)
r = radius of circle (0.75 m)

The centripetal force is the resultant of the forces of tension and gravity, and points upward (same direction as the tension force) since the tension force is greater.

Therefore:
$\frac{mv^2}{r} = T - Mg$

We can solve the equation for 'v':

$mv^2 = r(T - Mg) \\\\v^2 = \frac{r(T - Mg)}{m}\\\\v = \sqrt{\frac{r(T - Mg)}{m}}$

Plug in values and solve.

$v = \sqrt{\frac{(0.75)(40 - 1.2(9.8))}{1.2}} = \boxed{4.201 \frac{m}{s}}$

3 0

2 years ago

ad for the distance from the sun tothe earth is 1.5 x 10"m. how long does it take for light from ths sun to reach the eath? give

Alexandra [31]

Answer:

About 8.3 minutes

Explanation:

Use the formula for velocity as the distance covered by the light divided the time it takes: $[tex]velocity=\frac{distance}{time}$ [/tex]

Use the information about the speed of light in vacuum: $300000000 \frac{m}{s} = 3*10^{8} \frac{m}{s}$

and the information you are given regarding the distance between Sun and Earth: $1.5 * 10^{11} m$

to solve the first velocity equation for the unknown time "t":

$velocity=\frac{distance}{time} \\3*10^8\frac{m}{s} =\frac{1.5*10^11 m}{t} \\t=\frac{1.5*10^11 }{3*10^8} s= 500 s$

we can convert second into minutes by dividing by 60: 500 s = 500/60 minutes = 8.3333... minutes

5 0

3 years ago

Light travels at 3. 0 × 108 m/s in a vacuum and slows to 2. 0 × 108 m/s in glass. What is the index of refraction of glass?.

Sergio039 [100]

The required value of the index of refraction of glass is 1.5.

Given data:

The speed of light in a vacuum is, $c = 3.0 \times 10^{8} \;\rm m/s$ .

The speed of light in a glass is, $v = 2.0 \times 10^{8} \;\rm m/s$ .

Light has the tendency to travel from one medium to another, then the difference between the speeds of light in various mediums is determined by a term, known as the index of refraction. The mathematical expression for the index of refraction of glass is,

n = c / v

Solving as

$n = \dfrac{3.0 \times 10^{8}}{2.0 \times 10^{8}}\\\\n = 1.5$

Thus, we can conclude that the required value of the index of refraction of glass is 1.5.

Learn more about the index of refraction here:

brainly.com/question/17156275

5 0

2 years ago

A bus has velocity of 20 m/s towards east and another bus has velocity of 15 m/s in west direction . if they start to move from

Snezhnost [94]

Answer:

3.8 km

Explanation:

Eastern Side Bus

Velocity = 20m/s

Covers distance in 2 min (120sec) = 20×120 = 2400m = 2 km

Western Side Bus

Velocity = 15m/s

Covers distance in 2 min (120sec) = 15×120 = 1800m = 1.8 km

Separation Distance = 2+1.8 = 3.8 km

7 0

3 years ago