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3 years ago

What kind of mirrors are typically used for security purposes?

Physics

1 answer:

fredd [130]3 years ago

6 0

Answer:

CONVEX

Explanation:

BECOZ IT HELPS TO GET A WIDER VIEW

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A cloud of interstellar gas is rotating. Because the gravitational force pulls the gas particles together, the cloud shrinks, an

Fynjy0 [20]

Answer:

Greater than

Explanation:

Here, angular momentum is conserved.

$l_1\omega_1 =l_2\omega_2$

When the cloud shrinks under the right conditions, a star may be formed.

Thus, Diameter of clouds are much higher than a star.

Moment of inertia of cloud is greater than the star's inertial.

so, angular velocity of the star would be greater than angular velocity of the rotating gas.

3 0

3 years ago

Read 2 more answers

Why won’t anyone help me please anybody help me I really need help .

irga5000 [103]

Answer:

1➡️ this is the method of decomposition

2➡️ H2 and O2

3➡️ b

sorry if I am wrong

8 0

2 years ago

What are the seven different forms of energy? Give an example of each.

wel

Answer:

Form of energy: Example

1. Light energy: Electromagnetic radiation

2. Nuclear energy: Nuclear fission

3. Chemical energy: Energy stored in plant matter

4. Electrical energy: Lightning

5. Thermal energy: A hot surface

6. Sound energy: A tuning fork

7. Solar energy: Energy from the Sun

8. Mechanical energy: A moving vehicle

5 0

2 years ago

A high-speed flywheel in a motor is spinning at 450 rpm when a power failure suddenly occurs. The flywheel has mass 40.0 kg and

alexira [117]

Answer:

A) $\omega_f=17.503\ rad.s^{-1}$

B) $t=55.6822\ s$

C) $\theta=1312\ rad$

Explanation:

Given:

mass of flywheel, $m=40\ kg$

diameter of flywheel, $d=0.72\ m$

rotational speed of flywheel, $N_i=450\ rpm \Rightarrow \omega_i=\frac{450\times 2\pi}{60} =15\pi\ rad.s^{-1}$

duration for which the power is off, $t_0=35\ s$

no. of revolutions made during the power is off, $\theta=180\times 2\pi=360\pi\ rad$

<u>Using equation of motion:</u>

$\theta=\omega_i.t+\frac{1}{2} \alpha.t^2$

$360\pi=15\pi\times 35+\frac{1}{2} \times \alpha\times35^2$

$\alpha=-0.8463\ rad.s^{-2}$

Negative sign denotes deceleration.

Now using the equation:

$\omega_f=\omega_i+\alpha.t$

$\omega_f=15\pi-0.8463\times 35$

$\omega_f=17.503\ rad.s^{-1}$ is the angular velocity of the flywheel when the power comes back.

Here:

$\omega_f=0\ rad.s^{-1}$

Now using the equation:

$\omega_f=\omega_i+\alpha.t$

$0=15\pi-0.8463\times t$

$t=55.6822\ s$ is the time after which the flywheel stops.

Using the equation of motion:

$\theta=\omega_i.t+\frac{1}{2} \alpha.t^2$

$\theta=15\pi\times 55.68225-0.5\times 0.8463\times 55.68225^2$

$\theta=1312\ rad$ revolutions are made before stopping.

3 0

2 years ago

Kenny wants to get to Washington DC within 4 hours. Washington DC is 133 miles away from where he is. What is the avg speed he m

umka21 [38]

He must travel 35 mph

4 0

2 years ago