D. Binary Stars
Well, galaxies are not stars at all rather they are collection of stars, nebulae, globular clusters and stuff like this.
Meteoroids are something entirely different.
Constellations are the pattern of stars.
So, "Binary Stars" is the Right One.
Answer:
a) 50μC
b) 37.45 m/s
Explanation:
a) If the spheres are connected the charge in both spheres tends to be equal. This because is the situation of minimum energy.
Thus, you have:

Hence, each sphere has a charge of 50μC.
b) You use the fact that the total work done by the electric force is equal to the change in the kinetic energy of the sphere. Then, you use the following equations:
![\Delta W=\Delta K\\\\\int_{0.4}^\infty Fdr=\frac{1}{2}m[v^2-v_o^2]\\\\F=k\frac{Q^2}{r^2}\\\\v_o=0m/s\\\\m=0.08kg\\\\kQ^2\int_{0.4}^{\infty} \frac{dr}{r^2}=kQ^2[-\frac{1}{r}]_{0.4}^{\infty}=\frac{kQ^2}{0.4m}=\frac{(8.98*10^9Nm^2/C^2)(50*10^{-6}C)^2}{0.4m}\\\\kQ^2\int_{0.4}^{\infty} \frac{dr}{r^2}=56.125J](https://tex.z-dn.net/?f=%5CDelta%20W%3D%5CDelta%20K%5C%5C%5C%5C%5Cint_%7B0.4%7D%5E%5Cinfty%20Fdr%3D%5Cfrac%7B1%7D%7B2%7Dm%5Bv%5E2-v_o%5E2%5D%5C%5C%5C%5CF%3Dk%5Cfrac%7BQ%5E2%7D%7Br%5E2%7D%5C%5C%5C%5Cv_o%3D0m%2Fs%5C%5C%5C%5Cm%3D0.08kg%5C%5C%5C%5CkQ%5E2%5Cint_%7B0.4%7D%5E%7B%5Cinfty%7D%20%5Cfrac%7Bdr%7D%7Br%5E2%7D%3DkQ%5E2%5B-%5Cfrac%7B1%7D%7Br%7D%5D_%7B0.4%7D%5E%7B%5Cinfty%7D%3D%5Cfrac%7BkQ%5E2%7D%7B0.4m%7D%3D%5Cfrac%7B%288.98%2A10%5E9Nm%5E2%2FC%5E2%29%2850%2A10%5E%7B-6%7DC%29%5E2%7D%7B0.4m%7D%5C%5C%5C%5CkQ%5E2%5Cint_%7B0.4%7D%5E%7B%5Cinfty%7D%20%5Cfrac%7Bdr%7D%7Br%5E2%7D%3D56.125J)
where you have used the Coulomb constant = 8.98*10^9 Nm^2/C^2
Next, you equal the total work to the change in K:

hence, the speed of the spheres is 37.45 m/s
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The force of friction is equal to the product of the vertical force applied by the surface to the object in the coefficient of friction.
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In this question ,
surface vertical force = Weight of the object
Thus ;
svf = ( mass ) × ( gravity acceleration )
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If gravity acceleration is 10 :
svf = 10 × 10 = 100 N
So ;
frictional force = 100 × 0.20
frictional force = 20 N
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If gravity acceleration is 9.8 :
svf = 10 × 9.8 = 98 N
So ;
frictional force = 98 × 0.20
frictional force = 19.6 N
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Answer:
Resistors in series in the circuit must always have the same current
Explanation:
Resistors are said to be connected in series if they are connected one after another.
The total resistance in the circuit with resistors connected in series is equal to the sum of individual resistances.
Individual resistors in series do not get the total source voltage. Total source voltage divide among them.
Answer:
Explanation:
Considering non - relativistic approach : ----
Speed of electron = 1 % of speed of light
= .01 x 3 x 10⁸ m /s
= 3 x 10⁶ m /s
Kinetic energy of electron = 1/2 m v²
= .5 x 9.1 x 10⁻³¹ x ( 3 x 10⁶ )²
= 40.95 x 10⁻¹⁹ J
Kinetic energy in electron comes from lose of electrical energy equal to
Ve where V is potential difference under which electron is accelerated and e is electronic charge .
V x e = kinetic energy of electron
V x 1.6 x 10⁻¹⁹ = 40.95 x 10⁻¹⁹
V = 25.6 Volt .