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3 years ago

Why do we need optics now a days?

1 answer:

7 0

We need optics to help aid people who have short or long sightedness.
we need optics to be able to watch TV
we need optics to be able to use the internet at high speeds

there are a tonne of reasons why we need optics.

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1. How would you describe the area in which you live? Use terms such as desert, prairie, or

salantis [7]

Answer:

forest rual area

Explanation:

because thats where i live

5 0

3 years ago

Read 2 more answers

Can anyone explain<br>if knows

Aleks [24]

Answer:

Sry I’m just trying to get my points :(

Explanation:

Better luck nest time I would help if I was smart enough but currently I’m as d u m b as a rock...

5 0

3 years ago

Read 2 more answers

It has been suggested, and not facetiously, that life might have originated on Mars and been carried to Earth when a meteor hit

damaskus [11]

Answer:

$a=3125000 m/s^2\\a=3.125*10^6 m/s^2$

Acceleration, in m/s, of such a rock fragment = $3.125*10^6m/s^2$

Explanation:

According to Newton's Third Equation of motion

$V_f^2-V_i^2=2as$

Where:

$V_f$ is the final velocity

$V_i$ is the initial velocity

a is the acceleration

s is the distance

In our case:

$V_f=V_{escape}, V_i=0,s=4 m$

So Equation will become:

$V_{escape}^2-V_i^2=2as\\V_{escape}^2-0=2as\\V_{escape}^2=2as\\a=\frac{V_{escape}^2}{2s}\\a=\frac{(5*10^3m)^2}{2*4}\\a=3125000 m/s^2\\a=3.125*10^6 m/s^2$

Acceleration, in m/s, of such a rock fragment = $3.125*10^6m/s^2$

5 0

3 years ago

A train is moving along a horizontal track. A pendulum suspended from the roof makes an angle of 4° with the vertical. If g=10m/

nataly862011 [7]

Answer:

Train accaleration = 0.70 m/s^2

Explanation:

We have a pendulum (presumably simple in nature) in an accelerating train. As the train accelerates, the pendulum is going move in the opposite direction due to inertia. The force which causes this movement has the same accaleration as that of the train. This is the basis for the problem.

Start by setting up a free body diagram of all the forces in play: The gravitational force on the pendulum (mg), the force caused by the pendulum's inertial resistance to the train(F_i), and the resulting force of tension caused by the other two forces (F_r).

Next, set up your sum of forces equations/relationships. Note that the sum of vertical forces (y-direction) balance out and equal 0. While the horizontal forces add up to the total mass of the pendulum times it's accaleration; which, again, equals the train's accaleration.

After doing this, I would isolate the resulting force in the sum of vertical forces, substitute it into the horizontal force equation, and solve for the acceleration. The problem should reduce to show that the acceleration is proportional to the gravity times the tangent of the angle it makes.

I've attached my work, comment with any questions.

Side note: If you take this end result and solve for the angle, you'll see that no matter how fast the train accelerates, the pendulum will never reach a full 90°!