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2 years ago

Which two chemists organized elements based on properties such as how the elements react or whether they are solid or liquid

Physics

2 answers:

Lelechka [254]2 years ago

5 0

Doberiner and lavoiser

Basile [38]2 years ago

3 0

Answer:

Antoine Lavoisier and Johann Döbereiner

Explanation:

One of the very first attempt to classify the elements was made in 1789 by Antoine Lavoisier who grouped all the elements based on their properties into whether they are gases, metals or non metals and earths metals.

Johann Döbereiner in 1829, recognised triads of elements with similar chemical properties and showed that the properties of the element that is in the middle of other two elements can be predicted from the properties of the other two.

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A 0.5 μF and a 11 μF capacitors are connected in series. Then the pair are connected in parallel with a 1.5 μF capacitor. What i

NISA [10]

Answer:

$C_{eq}=1.97\ \mu F$

Explanation:

Given that,

Capacitance 1, $C_1=0.5\ \mu F$

Capacitance 2, $C_2=11\ \mu F$

Capacitance 3, $C_3=1.5\ \mu F$

C₁ and C₂ are connected in series. Their equivalent is given by :

$\dfrac{1}{C'}=\dfrac{1}{C_1}+\dfrac{1}{C_2}$

$\dfrac{1}{C'}=\dfrac{1}{0.5}+\dfrac{1}{11}$

$C'=0.47\ \mu F$

Now C' and C₃ are connected in parallel. So, the final equivalent capacitance is given by :

$C_{eq}=C'+C_3$

$C_{eq}=0.47+1.5$

$C_{eq}=1.97\ \mu F$

So, the equivalent capacitance of the combination is 1.97 micro farad. Hence, this is the required solution.

3 0

2 years ago

For a specific volume of 0.2 m3/kg, find the quality of steam if the absolute pressure is (a) 40 kPa and (b) 630 kPa. What is th

ICE Princess25 [194]

Answer:

$x=0.0498$

$x'=0.659$

Explanation:

Specific Volume $V=0.2m_3/kg$

Absolute Pressure (a) $P_a= 40kpa$

Giving

$T_a=75.87$

$v_f=1.265*10^{-3}m^3/kg$

$v_g=3.993m^3/kg$

(b) $P_a= 630kpa$

Giving

$T_b=160.13C$

$v_f'=1.10282*10^{-3} m^3/kg$

$v_g'=0.30286 m^3/kg$

(a)

Generally the equation for quality of Steam X is mathematically given by

$x=\frac{v-v_f}{v_g-v_f}$

$x=\frac{0.2-1.0265*10^{-3}}{3.993-1.0265*10^{-3}}$

$x=0.0498$

(b)

Generally the equation for quality of Steam X is mathematically given by

$x'=\frac{v-v_f'}{v_g'-v_f'}$

$x'=\frac{0.2-1.10*10^{-3}}{3.30-1.1*10^{-3}}$

$x'=0.659$

4 0

2 years ago

What is the average speed of an aircraft which travels 600m in 10 seconds ？

matrenka [14]

Answer:

60 meters per second

Explanation:

600/10=60

8 0

2 years ago

A football is kicked from the ground with a velocity of 38m/s at an angle of 40 degrees and eventually lands at the same height.

Anastasy [175]

Initially, the velocity vector is $\langle 38cos(40^{\circ}),38sin(40^{\circ}) \rangle=\langle 29.110, 24.426 \rangle$ . At the same height, the x-value of the vector will be the same, and the y-value will be opposite (assuming no air resistance). Assuming perfect reflection off the ground, the velocity vector is the same. After 0.2 seconds at 9.8 seconds, the y-value has decreased by $4.9(0.2)^2$ , so the velocity is $\langle 29.110, 24.426-0.196 \rangle = \langle 29.110, 24.23 \rangle$ .

Converting back to direction and magnitude, we get $\langle r,\theta \rangle=\langle \sqrt{29.11^2+24.23^2},tan^{-1}(\frac{29.11}{24.23}) \rangle = \langle 37.87,50.2^{\circ}\rangle$

4 0

2 years ago

A force F of magnitude 2x^3 is applied to stop a particle moving with an initial velocity of v0. The particle travels from x=0 t

3241004551 [841]

Answer:

Explanation:

Given that

F=2x³

Work is given as

The range of x is from x=0 to x=D

W=-∫f(x)dx

Then,

W=-∫2x³dx from x=0 to x=D

W=- 2x⁴/4 from x=0 to x=D

W=-2(D⁴/4-0/4)

W=-D⁴/2

W=1/2D⁴

The correct answer is F

5 0

2 years ago