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-BARSIC- [3]
2 years ago
12

A. A cord passing over an easily turned pulley (one that is both massless and frictionless) has 7kg mass hanging from one end an

d a 9kg mass hanging from the other end as shown below. G 7.0 kg 9.0 ks This arrangement is known as Atwood's machine. Calculate the (i). acceleration of the masses (ii). tension in the cord. [2.5 ​
Physics
1 answer:
Zepler [3.9K]2 years ago
6 0

Answer:

M g = M a = a (9 - 7) kg      with the two masses going in different directions

(7 + 9) kg * g = a * 2 kg       2 kg effective in prducing acceleration

a = 16 / 2 * g = 9.8 m/s^2 / 8 = 1.23 m/s^2

M1 a = T - M1 * g        T producing upward acceleration of 1.23 m/s^2

T = 7 (a + g) = 7 * 11 = 77 N

Check:

M2 a =  M2 * g - T          M2 producing downward acceleration

T = M2 (g - a) = 9 * (9.8 - 1.23) = 77 N

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A less massive moving object has an elastic collision with a more massive object that is not moving. Compare the initial velocit
stepladder [879]

Assume that the small-massed particle is m and the heavier mass particle is M.

Now, by momentum conservation and energy conservation:

   mv = mv_{m} + Mv_{M}

   mv^{2} = mv^{2}_{m} + Mv^{2}_{M}

Now, there are 2 solutions but, one of them is useless to this question's main point so I excluded that point. Ask me in the comments if you want the excluded solution too.

   v_{m} = v\frac{m - M}{m + M}\\\\\\v_{M} = v\frac{m + M}{m + M}\\

So now, we see that v_{m} < 0 and v_{M} > 0. So therefore, the smaller mass recoils out.

Hope this helps you!

Bye!

7 0
3 years ago
Calculate the change in entropy as 0.3071 kg of ice at 273.15 K melts. (The latent heat of fusion of water is 333000 J / kg)
Ostrovityanka [42]

Answer:

374.39 J/K

Explanation:

Entropy: This can be defined as the degree of disorder or randomness of a substance.

The S.I unit of entropy is J/K

ΔS = ΔH/T ..................................... Equation 1

Where ΔS = entropy change, ΔH = Heat change, T = temperature.

ΔH = cm................................... Equation 2

Where,

c = specific latent heat of fusion of water = 333000 J/kg, m = mass of ice = 0.3071 kg.

Substitute into equation 2

ΔH = 333000×0.3071

ΔH = 102264.3 J.

Also, T = 273.15 K

Substitute into equation 1

ΔS = 102264.3/273.15

ΔS = 374.39 J/K

Thus, The change in entropy = 374.39 J/K

3 0
3 years ago
In the photoelectric effect, the greater the frequency of the illuminating light, the greater the:_______
TEA [102]

Answer:

B. Maximum velocity of ejected electrons.

Explanation:

The ejection of electrons form a metal surface when the metal surface is exposed to a monochromatic electromagnetic wave of sufficiently short wavelength or higher frequency (or equivalently, above a threshold frequency),  which leads to the enough energy of the wave to incident and get absorbed to the exposed surface emits electrons. This phenomenon is known as the photoelectric effect or photo-emission.

The minimum amount of energy required by a metal surface to eject an electron from its surface is called work function of metal surface.

The electrons thus emitted are called photo-electrons.

The current produced as a result is called photo electricity.

Energy of photon is given by:

E=h.\nu

where:

h = Planck's constant

\nu= frequency of the incident radiation.

8 0
3 years ago
Without friction, what is the mass of an ball accelerating at 1.8 m/sec2 to which an
Juli2301 [7.4K]

Answer:

<h2>23.33 kg </h2>

Explanation:

The mass of the object can be found by using the formula

m =  \frac{f}{a}  \\

f is the force

a is the acceleration

From the question we have

m  = \frac{42}{1.8}   = 23.3333... \\

We have the final answer as

<h3>23.33 kg</h3>

Hope this helps you

4 0
2 years ago
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[10 POINTS ❗️❗️ and brainlist :)]
ludmilkaskok [199]
The answer to this is D
6 0
3 years ago
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