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3 years ago

As a pendulum swings back and forth __________.

Physics

1 answer:

Evgesh-ka [11]3 years ago

4 0

Answer:

E. All of the above.

Explanation:

These are the equations for potential (PE) and kinetic energy (KE):

PE = m · g · h

Where:

m = mass of the object.

g = acceleration due to gravity.

h = height.

KE = 1/2 · m · v²

Where:

m = mass.

v = speed.

At the end points of its swings, the pendulum is at its maximum height and its velocity is zero (for an instant). Then all the energy at these points is potential (answer B).

As the pendulum swings back from the end point it starts to lose height and acquires kinetic energy until it reaches the lowest part of the of its swing. At this point, all the potential energy was transformed into kinetic energy. The potential energy will be zero (because the height is zero) and due to energy conservation, the energy that once was potential energy has to be transformed into some kind of energy, in this case, into kinetic energy (we assume there is no air resistance, in which case some energy would be transformed into thermal energy as well, i.e., heat). (answer A and D).

After the lowest point, the pendulum acquires height (potential energy increases) and, due to the acceleration of gravity, it starts to lose velocity (kinetic energy decreases). Due to conservation of energy, the increase in potential energy must be equal to the decrease in kinetic energy. The kinetic energy is transformed into potential energy (answer C).

Then, the answer is E. All answers are correct.

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3 years ago

You need a 450 micrograms sample of gold,but you only have a mass balance that measures in decigrams. Convert the amount of gold

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It is the 459 of it comparing

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2 years ago

Vector A has a magnitude of 63 units and points west, while vector B has the same magnitude and points due south. Find the magni

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Given :

Vector A has a magnitude of 63 units and points west, while vector B has the same magnitude and points due south.

To Find :

The magnitude and direction of

a) A + B .

b) A - B.

Solution :

Let , direction in north is given by +j and east is given by +i .

So , $A=-63i$ and $B=63j$

Now , A + B is given by :

$A+B=-63i+63j$

$| A+B | = 63\sqrt{2}$

Direction of A+B is 45° north of west .

Also , for A-B :

$A-B=-63i-63j$

$|A-B|=63\sqrt{2}$

Direction of A-B is 45° south of west .

( When two vector of same magnitude which are perpendicular to each other are added or subtracted the resultant is always 45° from each of them)

Hence , this is the required solution .

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2 years ago

An experiment is set up to test the angular resolution of an optical device when red light (wavelength ????r ) shines on an aper

Neko [114]

Explanation:

As per Rayleigh criterion, the angular resolution is given as follows:

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3 years ago

A freight train rolls along a track with considerable momentum. If it were to roll at the same speed but had twice as much mass,

fomenos

Answer:

The momentum would be doubled

Explanation:

The magnitude of the momentum of the freight train is given by:

$p=mv$

where

m is the mass of the train

v is its speed

In this problem, we have that the speed of the train is unchanged, while the mass of the train is doubled:

$m'=2m$

therefore, the new momentum is

$p'=m'v=(2m)v=2(mv)=2p$

so, the momentum has also doubled.

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2 years ago