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3 years ago

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Select the correct answer.

1 answer:

Goshia [24]3 years ago

4 0

Answer:

Option C.

Polarization takes place!

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A block of mass 0.490 kg is pushed against a horizontal spring of negligible mass until the spring is compressed a distance x. T

Dennis_Churaev [7]

Answer:

The value of x is $x = 0.1955\ m$

The value of the velocity at the top is $v_{top} = 2.25 \ m/s$

Explanation:

The diagram of this process is on the first uploaded image

From the question we are told that

The mass of the block is $m_b = 0.490kg$

The distance of compression is $x$

The force constant is $k = 450 N/m$

The radius of the circular track is $R =1.00m$

The speed at the bottom of the track is $v_A = 13.4 \ m/s$

The frictional force experienced is $F_f = 7.00 \ N$

Now looking at this process we see that the potential energy of the spring is been transformed into the kinetic energy of the block . So,

$PE \ of \ spring = KE \ of \ block$

mathematically i.e

$\frac{1}{2}k x^2 = \frac{1}{2} m_bv^2_A$

$0.5 * 450 * x^2 = 0.5 * 0.490 * 13.4^2$

Making x the subject of the formula

$x = \sqrt{\frac{0.5 * 0.490 * 13.4^2}{ 0.5 * 450} }$

$= 0.1955\ m$

The average workdone by friction is $W_f = F_f * \pi$

Here $\pi is \ the\ net\ displacement$

$W_f = 7 * 3.142$

$= 21.99 J$

The kinetic energy at the bottom is

$KE = \frac{1}{2} * 0.490 * 13.4^2$

$= 43.99 \ N$

The potential energy gained at the top of the circle is

$PE = m_bgh$

Here h is the height which is equal to d(diameter) = 2r = 2 × 1 = 2 m and

g is acceleration due to gravity $= 9.8m/s^2$

Now substituting values

$PE = 0.490 * 9.8 *2$

$=9.604 J$

Since energy is can not be created nor destroyed but transformed according to first law of thermodynamics

$KE_{at \bottom} = PE _ {\ at \ top } + W_f + KE_{\ at \ top}$

$43.99 = 9.604 +21.99 + [\frac{1}{2} m_b * v_{top} ^2]$

$12.369= [2.45* v_{top} ^2]$

$v_{top} =\sqrt{\frac{12.369}{2.45} }$

$= 2.25 \ m/s$

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What was the hiker's average velocity during Part A of the hike?

jarptica [38.1K]

Answer is C. 4km/h east

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Astronomy can best be described as a/an

stiks02 [169]

C., cause stars aren't located in earth's atmosphere or " the interior part of Earth" and daily horoscope is a more astrology thing, and Air Force pilot on a Naval carrier? Come on now.

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4 years ago

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Arysha enjoys playing lacrosse on the school team. Suppose Arysha throws a lacrosse ball with a force of 6 N, and the resulting

olasank [31]

Answer:

$Mass = 0.14kg$

Explanation:

Given

$Force = 6N$

$Acceleration = 43m/s^2$

Required

Determine the mass of the ball

This question will be answered using Newton's second law of motion.

Which states that

$Force = Mass * Acceleration$

Substitute values for Force and Acceleration

$6N = Mass * 43m/s^2$

Make Mass the subject

$Mass = \frac{6N}{43m/s^2}$

$Mass = 0.13953488372$

$Mass = 0.14kg$ --- (approximated)

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Predict whether sound will would travel faster in air in summer or in winter?

Arisa [49]

In summer because the air in summer is less dense.

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