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3 years ago

Which of these statements best represents the law of conservation of energy

Physics

1 answer:

Shkiper50 [21]3 years ago

5 0

Energy cannot be created or destroyed. This statement is known as law of conservation of energy, and it implies that whenever a certain form of energy does change, the loss of this form of energy must have converted into an another type of energy. A typical example is an object falling to the ground: initially, the object has gravitational potential energy. As the object falls down, it loses potential energy (since its altitude from the ground decreases), but it acquires kinetic energy (because its velocity increases). In this example, potential energy has converted into kinetic energy, but the total energy of the object has remained constant.

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Calculate the TOTAL mechanical energy of pendulum is it swings from his highest point to its lowest point. Pendulum mass is 4

Lerok [7]

Answer:

its should be 2.0 and 4.5 on it

3 0

3 years ago

A ball starts from rest and accelerates at a constant rate of 1.0m/s to a final velocity of

den301095 [7]

Answer:

Time taken to reach final velocity = 5.5 second

Explanation:

Given:

Initial velocity (Starting from rest)(u) = 0 m/s

Acceleration of ball (a) = 1 m/s²

Final velocity (v) = 5.5 m/s

Find:

Time taken to reach final velocity

Computation:

Using first equation of motion;

v = u + at

where,

v = final velocity

u = initial velocity

a = acceleration

t = time taken

5.5 = 0 + (1)(t)

5.5 = t

Time taken to reach final velocity = 5.5 second

8 0

3 years ago

How long does it take a 22 kW steam engine to do 5.6 × 107 J of work? Answer in units of s.

Lena [83]

<h2>Time needed is 2545.45 seconds.</h2>

Explanation:

We know equation for power

$\texttt{Power = }\frac{\texttt{Work}}{\texttt{Time}}$

Here we need to find time when for a 22 kW steam engine to do 5.6 × 10⁷ J of work.

Work = 5.6 × 10⁷ J

Power = 22 kW = 22 x 10³ W

Substituting

$\texttt{Power = }\frac{\texttt{Work}}{\texttt{Time}}\\\\22\times 10^3=\frac{5.6\times 10^7}{\texttt{Time}}\\\\\texttt{Time}=2545.45s$

Time needed is 2545.45 seconds.

5 0

3 years ago

Which one of the following SI base units is not matched to the correct unit of measurement?

laiz [17]

<span><span>A. </span>Length: km<span>

The Si units of all the left measurements are true thus, in length the typical and standard SI unit is meter. SI units, also called as International Standard of Units, is composed of the following systematized units of physical measure which include, mole (amount of substance), candela (luminous intensity), kelvin (temperature), ampere (electric current), second (time), kilogram (mass), and meter (length). Hence, these measures spheres in multiplication or division by power of 10, increase or decrease in measure.</span></span>

3 0

4 years ago

Determine the normal boiling point of a substance whose vapor pressure is 55.1 mm hg at 35°c and has a δhvap of 32.1 kj/mol.

Novosadov [1.4K]

Answer:

389.78681 K

Explanation:

$P_1$ = Initial pressure = 55.1 mmHg

$P_2$ = Final pressure = 1 atm = 760 mmHg

$T_2$ = Boiling point

$T_1$ = Initial temperature = 35°C

$\Delta H_{vap}$ = Heat of vaporization = 32.1 kJ/mol

From the Clausius-Claperyon equation

$ln\dfrac{P_2}{P_1}=(-\dfrac{\Delta H_{vap}}{R})(\dfrac{1}{T_2}-\dfrac{1}{T_1})\\\Rightarrow \dfrac{1}{T_2}=-ln\dfrac{P_2}{P_1}\dfrac{R}{\Delta H_{vap}}+\dfrac{1}{T_1}\\\Rightarrow \dfrac{1}{T_2}=-ln\dfrac{760}{55.1}\dfrac{8.314}{32.1\times 10^{3}}+\dfrac{1}{273.15+35}\\\Rightarrow T_2=\left(-ln\left(\frac{760}{55.1}\right)\frac{8.314}{32.1\times \:10^3}+\frac{1}{273.15+35}\right)^{-1}\\\Rightarrow T_2=389.78681\ K$

The normal boiling point of the substance is 389.78681 K

3 0

3 years ago