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3 years ago

What is necessary to designate a position? A. a reference point B. a direction C. fundamental units D. motion E. all of these

Physics

1 answer:

max2010maxim [7]3 years ago

8 0

Answer:

E. all of these

Explanation:

The designation of a point in space all the points that necessary

- reference point

- a direction

- fundamental units

- a direction

- motion

all are necessary to designate a point in space. Hence option E is correct.

For example in simple harmonic motion we need to specify all the above factors of the object in order to designate the position of the object.

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Under which circumstances would protesters’ right to assembly most likely be protected?

ICE Princess25 [194]

Answer:

Explanation:

Mob violence is never protected. Organizers are always careful about not letting things get out of hand. Not D

That remark sort of applies to C as well. Property destruction is never protected.

B is something assemblies are allowed to do. So B.

A falls into the same category as C and D. You may not like the fact that he/she is doing something illegal, but you can't take away their privacy.

7 0

3 years ago

A student sits on a rotating stool holding two 3.09-kg masses. When his arms are extended horizontally, the masses are 1.08 m fr

schepotkina [342]

Answer:

The New angular speed is $w_f = 2.034 rad/s$

The Kinetic energy before the masses are pulled in is $KE_i = 3.101 \ J$

The Kinetic energy after the masses are pulled in is $KE_f = 8.192 \ J$

Explanation:

From the we are told that masses are 1.08 m from the axis of rotation, this means that

The radius $r =1.08m$

The mass is $m = 3.09\ kg$

The angular speed $w = 0.770 \ rad/sec$

The moment of inertia of the system excluding the two mass $I = 3.25 \ kg \cdot m^2$

New radius $r_{new} = 0.34m$

Generally the conservation of angular momentum can be mathematical represented as

$w_f = [\frac{I_i}{I_f} ]w_i .....(1)$

Where $w_f$ is the final angular speed

$w_i$ is the initial angular speed

$I_i$ is the initial moment of inertia

$I_f$ is the final moment of inertia

Moment of inertia is mathematically represented as

$I = m r^2$

Where I is the moment of inertia

m is the mass

r is the radius

So the Initial moment of inertia is given as

$I_i = moment \ of \ inertia \ of\ the \ two \ mass \ + 3.25 \ kg \cdot m^2$

$I_i = 2m r^2 + 3.25$

The multiplication by is because we are considering two masses

$I_i = 2 [(3.09)(1.08)^2] +3.25 = 10.46 kg \cdot m^2$

So the final moment of inertia is given as

$I_f = 2[(3.09)(0.34)^2] +3.25 = 3.96 \ kg \cdot m^2$

Substituting these values into equation 1

$w_f = [\frac{10.46}{3.96} ] * 0.77 = 2.034 \ rad/sec$

Generally Kinetic energy is mathematically represented in term of moment of inertia as

$KE = \frac{1}{2} * I * w^2$

Now considering the kinetic energy before the masses are pulled in,

$KE_i = \frac{1}{2} * I_i * w^2_i$

The Moment of inertia would be $I_i = 10.46 \ Kg \cdot m^2$

The Angular speed would be $w_i = 0.77 \ rad/s$

Now substituting these value into the equation above

$KE_i = \frac{1}{2} * (10.46) * (0.770)^2 = 3.101 J$

Now considering the kinetic energy after the masses are pulled in,

$KE_f = \frac{1}{2} * I_f * w^2_f$

The Moment of inertia would be $I_f = 3.96 \ Kg \cdot m^2$

The Angular speed would be $w_f = 2.034 \ rad/s$

Now substituting these value into the equation above

$KE_f= \frac{1}{2} *(3.96)(2.034)^2$

$= 8.192J$

8 0

3 years ago

You have two electrical devices plugged into the same socket in parallel and draws 120 V. The first device has a resistance of 2

erik [133]

The devices don't "draw" 120v. The 120v comes to your house from the power company. They decide it should be 120v and that's what they send you. It's hypothetically technically possible for you to change that, but if you try it, you'll definitely burn the house down.

The total resistance of those two devices in parallel is 6 and 2/3 ohms. That doesn't depend on what they're plugged into. It would still be 6 and 2/3 ohms if they were connected in parallel, wrapped in tissue, sealed in a jar of chicken soup and stored in a box on a high shelf.

But since they ARE plugged into 120v, they draw 18 Amperes from the socket, and they turn all of that electrical energy into 2160 watts of heat. That's about the same as a good size toaster oven, and you have to figure out a way to get rid of all that heat before you burn the house down.

4 0

3 years ago

Upon reaching a velocity of 100fps, the pilot of the airplane decides to abort the take off and applies brakes and stops the air

masha68 [24]

Answer:

5 ft/s²

Explanation:

u = Initial velocity = 100 ft/s

v = Final velocity = 0

s = Displacement = 1000 ft

a = Acceleration

From equation of motion