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Sever21 [200]
1 year ago
15

A 5-kg concrete block is lowered with a downward acceleration of 2.8 m/s2 by means of a rope. The force of the block on the Eart

h is: A. 35 N, down B. 35 N, up C. 14 N, down D. 14 N, up E. 49 N, up
Physics
1 answer:
maksim [4K]1 year ago
5 0

When the body touches the ground two types of Forces will be generated. The Force product of the weight and the Normal Force. This is basically explained in Newton's third law in which we have that for every action there must also be a reaction. If the Force of the weight is pointing towards the earth, the reaction Force of the block will be opposite, that is, upwards and will be equivalent to its weight:

F = mg

Where,

m = mass

g = Gravitational acceleration

F = 5*9.8

F = 49N

Therefore the correct answer is E.

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The loudness of a sound is inversely proportional to the square of your distance from the source of the sound. if your friend is
kirill [66]
Let loudness be L, distance be d, and k be the constant of variation such that the equation that would best represent the given above is,
                    L = k/(d^2)
For Case 1,
                       L1 = k/(d1^2)
For Case 2,
                       L2 = k/((d1/4)^2)
For k to be equal, L1 = 16L2. 
Therefore, the loudness at your friend's position is 16 times that of yours. 
5 0
2 years ago
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A 250 Hz tuning fork is struck and the intensity at the source is I1 at a distance of one meter from the source. (a) What is the
Zina [86]

Answer:

a) 0.0625 I_1

b) 3.16 m

Explanation:

<u>Concepts and Principles  </u>

The intensity at a distance r from a point source that emits waves of power P is given as:  

I=P/4π*r^2                         (1)

<u>Given Data</u>

f (frequency of the tuning fork) = 250 Hz

I_1 is the intensity at the source a distance r_1 = I m from the source.  

<u>Required Data</u>

- In part (a), we are asked to determine the intensity I_2 a distance r_2 = 4 in from the source.

- In part (b), we are asked to determine the distance from the tuning fork at which the intensity is a tenth of the intensity at the source.  

<u>solution:</u>

(a)  

According to Equation (1), the intensity a distance r is inversely proportional to the distance from the source squared:

I∝1/r^2

Set the proportionality:  

I_1/I_2=(r_2/r_1)^2                                 (2)

Solve for I_2 :  

I_2=I_1(r_2/r_1)^2  

I_2=0.0625 I_1

(b)  

Solve Equation (2) for r_2:  

r_2=(√I_1/I_2)*r_1

where I_2 = (1/10)*I_1:

r_2=(√I_1/1/10*I_1)*r_1

     =3.16 m

3 0
2 years ago
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Naily [24]

Answer:

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Explanation:

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now we have

m_1v_1 + m_2v_2 = 0

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now we have

34 v + 54 (3 m/s) = 0

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8 0
1 year ago
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s = displacement = 100m

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100 = 1.4t + (1/2)*0.2*t^2

t = 25.388s

and

Vf = 1.4 + 0.2(25.388)

Vf = 6.5 m/s

So the answer you are looking for is 6.5 m/s
7 0
2 years ago
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seraphim [82]
Either theory or evidence
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