Answer:
E=0.036 V/m
Explanation:
Given that
Resistivity ,ρ=2.44 x 10⁻⁸ ohms.m
d= 0.9 mm
L= 14 cm
I = 940 m A = 0.94 A
We know that electric field E
E= V/L
V= I R
R=ρL/A
So we can say that
E= ρI/A
Now by putting the values

E=0.036 V/m
Answer:

Explanation:
We know that for circular motion the centripetal acceleration
is:

where v is the speed and r is the radius.
The centripetal acceleration for the astronaut must be the gravitational acceleration due to the gravity, as there are no other force. So
.
The radius of the orbit must be the radius of the Moon, plus the 270 km above the surface




We can obtain the speed as:






And this is the orbital speed.
Answer:
1.F is the electrostatic force between charges (in Newtons),
2.q₁ is the magnitude of the first charge (in Coulombs),
3.q₂ is the magnitude of the second charge (in Coulombs),
4.r is the shortest distance between the charges (in m),
5.ke is the Coulomb's constant. It is equal to 8.98755 × 10⁹ N·m²/C² .
Answer:
★The second law of refraction
The ratio of sine of angle of incidence to the sine of angle of refraction is a constant for a light of given colour and for a given pair of media. This law is also called Snell's law of refraction. If 'i' is the angle of incidence and 'r' is the angle of refraction then, Sin i/Sin r = constant
This constant value is called the refractive index of the second medium with respect to the first.
The question involves a ping-pong ball that is held submerged in a bucket by a string attached to the bottom of the bucket.
The answer is the tension of the string will increase. This is because making the water salty increases its density, and consequently, increases its buoyancy. This is why sea water is more buoyant than fresh water. Therefore the ping pong is pushed more upwards by the water when salt is added than initially. This gives the string more tension.