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3 years ago

HELP I DON'T PAY ATTENTION ENOUGH

Physics

2 answers:

Setler [38]3 years ago

8 0

Answer:

I think 1 is d and 2 is A

Explanation:

but I may be wrong and I am so sorry if I am

nydimaria [60]3 years ago

6 0

Answer: Well the first one is D. The second one would be A because if you do the research and eliminate the other ones, these answers would have to be the correct ones following the reading and checking websites

Explanation:

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A heavy flywheel is accelerated (rotationally) by a motor that provides constant torque and therefore a constant angular acceler

ki77a [65]

Answer:

a) $t_1=\frac{w_1-w_o}{\alpha}=\frac{w_1}{\alpha}sec$

b) $\theta_1=\frac{w_1^2}{2\alpha}rad$

c) $t_2=\frac{\alpha t_1}{5\alpha}=\frac{t_1}{5}sec$

Explanation:

1) Basic concepts

Angular displacement is defined as the angle changed by an object. The units are rad/s.

Angular velocity is defined as the rate of change of angular displacement respect to the change of time, given by this formula:

$w=\frac{\Delat \theta}{\Delta t}$

Angular acceleration is the rate of change of the angular velocity respect to the time

$\alpha=\frac{dw}{dt}$

2) Part a

We can define some notation

$w_o=0\frac{rad}{s}$ ,represent the initial angular velocity of the wheel

$w_1=?\frac{rad}{s}$ , represent the final angular velocity of the wheel

$\alpha$ , represent the angular acceleration of the flywheel

$t_1$ time taken in order to reach the final angular velocity

So we can apply this formula from kinematics:

$w_1=w_o +\alpha t_1$

And solving for t1 we got:

$t_1=\frac{w_1-w_o}{\alpha}=\frac{w_1}{\alpha}sec$

3) Part b

We can use other formula from kinematics in order to find the angular displacement, on this case the following:

$\Delta \theta=wt+\frac{1}{2}\alpha t^2$

Replacing the values for our case we got:

$\Delta \theta=w_o t+\frac{1}{2}\alpha t_1^2$

And we can replace $t_1$ from the result for part a, like this:

$\theta_1-\theta_o=w_o t+\frac{1}{2}\alpha (\frac{w_1}{\alpha})^2$

Since $\theta_o=0$ and $w_o=0$ then we have:

$\theta_1=\frac{1}{2}\alpha \frac{w_1^2}{\alpha^2}$

And simplifying:

$\theta_1=\frac{w_1^2}{2\alpha}rad$

4) Part c

For this case we can assume that the angular acceleration in order to stop applied on the wheel is $\alpha_1 =-5\alpha \frac{rad}{s}$

We have an initial angular velocity $w_1$ , and since at the end stops we have that $w_2 =0$

Assuming that $t_2$ represent the time in order to stop the wheel, we cna use the following formula

$w_2 =w_1 +\alpha_1 t_2$

Since $w_2=0$ if we solve for $t_2$ we got

$t_2=\frac{0-w_1}{\alpha_1}=\frac{-w_1}{-5\alpha}$

And from part a) we can see that $w_1=\alpha t_1$ , and replacing into the last equation we got:

$t_2=\frac{\alpha t_1}{5\alpha}=\frac{t_1}{5}sec$

5 0

3 years ago

Which elements are metalloids

zhannawk [14.2K]

The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium....

7 0

4 years ago

The four lines observed in the visible emission spectrum of hydrogen tell us that

Gemiola [76]

Answer:

The correct answer is violet, blue, green, and red emission lines.

Explanation:

When samples of pure elements are heated they emit a continuous spectrum of electromagnetic radiation. When elements are heated at very high temperatures, the electrons get excited and they jump to consequent orbits and this results in transmission of electromagnetic radiation. The four lines visible in the emission spectrum of hydrogen are violet, blue, green, and red, the most intense of which is at 656 nanometre.

7 0

3 years ago

Lightning heats the surrounding air to ___. A. 30000C B. 300C C. 300000C D. 3000C

Blizzard [7]

A bolt of lightning, which can reach temperatures of roughly 30,000 kelvins (53,540 degrees Fahrenheit). The sun, on the other hand, is eclipsed in this case, its surface temperature is just 6,000 kelvins (10,340 degrees Fahrenheit)
So,it can be around 30,000 degrees.The answer is Choice A.

3 0

3 years ago

Read 2 more answers

In what condition do acceleration and deaccelration

Vera_Pavlovna [14]

Im not sure what are you asking about. But in physic/ mechanic usually when the object against gravity, its deceleration but when the object follow the gravity its acceleration

Also usually when the object move to the left side the speed will be negative (-) this is probably because of deceleration? since deceleration = -acceleration.

5 0

3 years ago