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3 years ago

A turntable with a radius of 8cm rotates at 45 rpm. What is the linear speed of a point on the outside rim?

Physics

1 answer:

fomenos3 years ago

8 0

Assuming the turntable is circular, its circumference is

(2 π) x (its radius) .

That's the distance covered by a point on its rim during every complete revolution.

The distance covered by the same point during 45 revolutions is

(45) x (2 π) x (radius).

So we can write . . .

Speed of the point = (45 rev/min) · (2 · π · 8 cm / rev)

Speed = (720 π) cm/minute

Speed = 12π cm/second

Speed = 37.7 cm/sec

<em>Speed = 0.377 m/s </em>

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monochromatic light from a distant source is incident on a slit 0.75 mm wide. on screen 2 m away, the distance from the central

hjlf

Displacement from the center line for minimum intensity is 1.35 mm , width of the slit is 0.75 so Wavelength of the light is 506.25.

<h3>How to find Wavelength of the light?</h3>

When a wave is bent by an obstruction whose dimensions are similar to the wavelength, diffraction is observed. We can disregard the effects of extremes because the Fraunhofer diffraction is the most straightforward scenario and the obstacle is a long, narrow slit.

This is a straightforward situation in which we can apply the

Fraunhofer single slit diffraction equation:

y = mλD/a

Where:

y = Displacement from the center line for minimum intensity = 1.35 mm

λ = wavelength of the light.

D = distance

a = width of the slit = 0.75

m = order number = 1

Solving for λ

λ = y + a/ mD

Changing the information that the issue has provided:

λ = 1.35 * 10^-3 + 0.75 * 10^-3 / 1*2

=5.0625 *10^-7 = 506.25

Wavelength of the light 506.25.

To learn more about Wavelength of the light refer to:

brainly.com/question/15413360

#SPJ4

5 0

1 year ago

What determines the number of possible sublevels?

Talja [164]

<h2>Hello!</h2>

The answer is A. the principal energy level

The principal energy level or principal quantum number n, tell us about the position of an determined electron in the energy levels relative to the greater average distance of an electron from the nucleus, the larger the value of n and the higher its energy.

The principal energy levels contains n sublevels, $n^{2}$ orbitals and $2n^{2}$ electrons.

For example, the number 1, has one orbital which is contained in a energy sublevel, its called s orbital, and it's just an orbital with 2 electrons.

Have a nice day!

7 0

3 years ago

Read 2 more answers

Effciency of a lever is never 100% or more. why?Give reason

Troyanec [42]

Answer:

Ideally, the work output of a lever should match the work input. However, because of resistance, the output power is nearly always be less than the input power. As a result, the efficiency would go below $100\%$ .

Explanation:

In an ideal lever, the size of the input and output are inversely proportional to the distances between these two forces and the fulcrum. Let $D_\text{in}$ and $D_\text{out}$ denote these two distances, and let $F_\text{in}$ and $F_\text{out}$ denote the input and the output forces. If the lever is indeed idea, then:

$F_\text{in} \cdot D_\text{in} = F_\text{out} \cdot D_\text{out}$ .

Rearrange to obtain:

$\displaystyle F_\text{in} = F_\text{out} \cdot \frac{D_\text{out}}{D_\text{in}}$

Class two levers are levers where the perpendicular distance between the fulcrum and the input is greater than that between the fulcrum and the output. For this ideal lever, that means $D_\text{in} > D_\text{out}$ , such that $F_\text{in} < F_\text{out}$ .

Despite $F_\text{in} < F_\text{out}$ , the amount of work required will stay the same. Let $s_\text{out}$ denote the required linear displacement for the output force. At a distance of $D_\text{out}$ from the fulcrum, the angular displacement of the output force would be $\displaystyle \frac{s_\text{out}}{D_\text{out}}$ . Let $s_\text{in}$ denote the corresponding linear displacement required for the input force. Similarly, the angular displacement of the input force would be $\displaystyle \frac{s_\text{in}}{D_\text{in}}$ . Because both the input and the output are on the same lever, their angular displacement should be the same:

$\displaystyle \frac{s_\text{in}}{D_\text{in}} =\frac{s_\text{out}}{D_\text{out}}$ .

Rearrange to obtain:

$\displaystyle s_\text{in}=s_\text{out} \cdot \frac{D_\text{in}}{D_\text{out}}$ .

While increasing $D_\text{in}$ reduce the size of the input force $F_\text{in}$ , doing so would also increase the linear distance of the input force $s_\text{in}$ . In other words, $F_\text{in}$ will have to move across a longer linear distance in order to move $F_\text{out}$ by the same $s_\text{out}$ .

The amount of work required depends on both the size of the force and the distance traveled. Let $W_\text{in}$ and $W_\text{out}$ denote the input and output work. For this ideal lever:

$\begin{aligned}W_\text{in} &= F_\text{in} \cdot s_\text{in} \\ &= \left(F_\text{out} \cdot \frac{D_\text{out}}{D_\text{in}}\right) \cdot \left(s_\text{out} \cdot \frac{D_\text{in}}{D_\text{out}}\right) \\ &= F_\text{out} \cdot s_\text{out} = W_\text{out}\end{aligned}$ .

In other words, the work input of the ideal lever is equal to the work output.

The efficiency of a machine can be measured as the percentage of work input that is converted to useful output. For this ideal lever, that ratio would be $100\%$ - not anything higher than that.

On the other hand, non-ideal levers take in more work than they give out. The reason is that because of resistance, $F_\text{in}$ would be larger than ideal:

$\displaystyle F_\text{in} = F_\text{out} \cdot \frac{D_\text{out}}{D_\text{in}} + F(\text{resistance})$ .

As a result, in real (i.e., non-ideal) levers, the work input will exceed the useful work output. The efficiency will go below $100\%$ ,

4 0

3 years ago

A length of copper wire has a resistance 29 Ω. The wire is cut into three pieces of equal length, which are then connected as pa

erik [133]

Answer:

3.222 ohms

Explanation:

If the total wire had a resistance of 29 ohms, when cut in three, each piece will have a resistance of 9.666 ohms.

As these three pieces (R1, R2 and R3) are now connected in parallel, the equivalent resistance R can be calculated using this equation:

1/R = 1/R1 + 1/R2 + 1/R3

1/R = 1/9.666 + 1/9.666 + 1/9.666

1/R = 3/9.666

R = 9.666/3 = 3.222 ohms

The resistance between A and B will be 3.222 ohms

6 0

3 years ago

If you weigh 38 kilograms on your bathroom scale, your weight in space will be ________.

harina [27]

Answer:

Less than 36kilo's

Explanation:

5 0

3 years ago