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Sphinxa [80]
3 years ago
5

A car advertisement states that a car can accelerate at 2 m/sec. The car starts from rest and accelerates to 70 km/hr. How much

time does it take to accelerate to 70 km/hr.​
Physics
1 answer:
Reptile [31]3 years ago
7 0

Answer:

9.72s

Explanation:

\pink{\frak{Given}}\begin{cases}\textsf{ A car starts from rest.}\\\textsf{It has an acceleration of 2m/s$^2$.}\\\textsf{ The final velocity of the car is 70km/hr.}\end{cases}

Here we need to find out the time that the car took to achieve the velocity of 70km/hr after starting from rest . Firstly convert the final velocity in m/s by multiplying it by 5/18 , as ,

\longrightarrow\sf 70km/hr = 70 \times \dfrac{5}{18} m/s =\bf 19.44\  m/s

  • As we know that the rate of change of velocity is known as acceleration , so ;

\longrightarrow\sf a =\dfrac{v - u}{t}

Plug in the respective values ,

\longrightarrow\sf 2m/s^2 = \dfrac{ 19.4 m/s -0m/s}{t} \\

Simplify ,

\longrightarrow\sf 2m/s^2 =\dfrac{19.4m/s}{t}

Cross multiply ,

\longrightarrow\sf t = \dfrac{19.44m/s}{2m/s^2}

Simplify

\longrightarrow\sf \boxed{\bf t = 9.72 s}

<h3>Hence the required answer is 9.72s.</h3>
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Calculate the number of moles of gas present in the sealed container at a
aliina [53]

Here volume of gas is not given so question is solved assuming volume as 1 L.

The number of moles of 1 L gas present in the sealed container at a

pressure of 125 kPa at 25 degrees Celsius is 0.0067 moles.

The ideal gas law equation can be written as

PV  = nR T

Here

P is the pressure of the gas in atm

V is the volume it occupies in L

n is the number of moles of gas present in the sample

R is the universal gas constant, equal to 0.0821 atm L/ mol K

T is the absolute temperature of the gas in Kelvin

Now, it's important to realize that the units you have for the volume, pressure, and temperature of the gas must match the unit used in the expression of the universal gas constant.

So

P = 125 kPa

1 atm = 760 kPa

P = 125/760 = 0.1644 atm

T = 25 degree celsius  = 25 +273 = 298 K

Taking V  = 1 L

So

n  = PV/RT

n = 0.1644 x 1 / 0.0821 x 298

n =  0.0067 moles

To learn more about the ideal gas law, please click on the link brainly.com/question/128737528

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8 0
2 years ago
How much force is needed to accelerate a 1,100 kg car at a rate of 1.5 m/s2?
Anna [14]
Assuming there is no force of friction...

F = ma
F = (1300kg)(1.5m/s^2)
F = 1950N
Just multiply mass by acceleration.
1300 x 1.5 = 1950N.
7 0
3 years ago
A 2.00-kg, frictionless block is attached to an ideal spring with force constant 300 N/mN/m. At t=0 t=0 the block has velocity -
slega [8]

Answer:

The amplitude of the spring is 32.6 cm.

Explanation:

It is given that,

Mass of the block, m = 2 kg

Force constant of the spring, k = 300 N/m

At t = 0, the velocity of the block, v = -4 m/s

Displacement of the block, x = 0.2 mm = 0.0002 m

We need to find the amplitude of the spring. We know that the velocity in terms of amplitude and the angular velocity is given by :

v=\omega\sqrt{A^2-x^2}

\omega=\sqrt{\dfrac{k}{m}}

\omega=\sqrt{\dfrac{300}{2}}    

\omega=12.24\ rad/s

So, \dfrac{v^2}{\omega^2}+x^2=A^2

\dfrac{(-4)^2}{(12.24)^2}+(0.0002)^2=A^2            

A = 0.326 m

or

A = 32.6 cm

So, the amplitude of the spring is 32.6 cm. Hence, this is the required solution.

4 0
4 years ago
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Ivenika [448]

Answer:

c

Explanation:

because the other would not make sense

3 0
3 years ago
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Elza [17]
The answer is a because it has a high melting tolerance 
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