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Alex
4 years ago
5

a motorcar is moving with a velocity of 108 km / h and it takes 4s to stop after the brakes are applied calculate the force exer

ted by the brakes on the motorcar if it's mass along with the passengers is 1000 kg​
Physics
2 answers:
vladimir1956 [14]4 years ago
7 0

Answer:

-7500 N

Explanation:

v₀ = 108 km/h = 30 m/s

v = 0 m/s

t = 4 s

a = Δv / Δt

a = (0 m/s − 30 m/s) / 4 s

a = -7.5 m/s²

F = ma

F = (1000 kg) (-7.5 m/s²)

F = -7500 N

NikAS [45]4 years ago
3 0

Answer:-7500

Explanation v₀ = 108 km/h = 30 m/s

v = 0 m/s

t = 4 s

a = Δv / Δt

a = (0 m/s − 30 m/s) / 4 s

a = -7.5 m/s²

F = ma

F = (1000 kg) (-7.5 m/s²)

F = -7500 N

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The theorem is stated as E = mc^{2} where c is the velocity of light and m is the mass converted into energy.

One take an example of fusion in sun where 4 hydrogen atoms combine to form a helium nucleus which are explained below-

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                                                      He_{2} ^{3}+H_{1} ^{1} =He_{2} ^{4} +e_{+1} ^{0} +energy

                                                       -----------------------------------------------------------------------

                                                        4H_{1} ^{1} = He_{2} ^{4} +2e_{+1} ^{0} +energy

Here e_{+1} ^{0} is the positron.

In this process very high temperature is needed which is approximately equal to the temperature of the sun i.e 10^{6} K

Such temperature is very difficult to initiate the reaction on the earth surface. It should be carried out in an sustainable way also .Otherwise It will cause nuclear hazards.

6 0
3 years ago
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Mariulka [41]

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w = 1.976 rpm

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We know by the question that:

r = 60.5m

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2.6m/s = w^2(60.5m)

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Finally we change the angular velocity from rad/s to rpm as:

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3 0
3 years ago
A pulley is most closely related to which simple machine?
MrRissso [65]

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alexandr402 [8]

Answer:

g'=63.74\ m/s^2

Explanation:

It is given that,

Weight of the person on Earth, W = 818 N

Weight of a person is given by the following formula as :

W=mg

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m=\dfrac{W}{g}

m=\dfrac{818\ N}{9.8\ m/s^2}

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The mass of an object is same everywhere. It does not depend on the location.

Let W' is the weight of the person on the surface of a nearby planet, W' = 5320 N

g' is the acceleration due to gravity on that planet. So,

g'=\dfrac{W'}{m}

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g'=63.74\ m/s^2

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6 0
3 years ago
Please answer this question for me and explain why.
horsena [70]

Answer:

D.None of these

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Let us call the 5kg mass m_2 and the 4kg mass m_1. If the tension in the string is T then for the mass m_2

(1). T-m_2g=-m_2a <em>(the negative sign on the right side indicates that acceleration is downwards)</em>

And for the mass m_1

(2). T-m_1g =m_1a<em> (the acceleration is upwards, hence the positive sign)</em>

Solving for T in the 2nd equation we get:

T =m_1a+m_1g,

and putting this into the 1st equation we get:

m_1a+m_1g-m_2g=-m_2a\\\\m_1a+m_2a = m_2g-m_1g\\\\a(m_1+m_2)= (m_2-m_1)g

\boxed{a= \dfrac{(m_2-m_1)}{(m_1+m_2)} g}

Back to the question:

Using the formula for the acceleration we find

a= \dfrac{(5kg-4kg)}{(5kg+4kg)} g

a = \dfrac{g}{9},

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7 0
3 years ago
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