Answer:
3.974 Joule
Explanation:
Diameter of ring = 7.7 cm
a = Distance from the center = d/2 = 3.85 cm = 0.0385 m
Q = Charge = 5 mC
q = Charge to move = 3.4 mC
k = Coulomb constant = 9×10⁹ Nm²/C²
Work done will be equal to Potential energy when mass is at center

∴ Work to move a tiny 3.4 mC charge from very far away to the center of the ring is 3.974 Joule
Answer:
The length of the object would shrink to zero which is not possible.
Explanation:
A rocket or any body cannot reach the speed of light because according to theory of relativity the and the Lorentz factor the length of the object would shrink to zero and the time dilation for that body would be infinite.
The Lorentz factor is given as:

where:
v = speed of the moving object
c = speed of light
If you have (1 x 10⁹) cubic meters of volume, and 1/2 gram of mass
in each cubic meter, then you have
(1/2 x 10⁹) grams = (5 x 10⁸) grams = (5 x 10⁵) kilograms of mass .
On Earth, that mass weighs 4,900,000 newtons .
(about 1,102,300 pounds)
(about 551 tons)
Answer:
Option B
Explanation:
Speed of a wave is denoted by:
v=fλ
where f is the frequency which is unchanged 15Hz and λ is the new wavelength which is 28m
v=fλ
