Answer:

Explanation:
Let's use Ohm's law:
or
(1)
Where:

We know the value of the voltage V, so we need to find the value of R in order to find I. Fortunately there is a relation between the resistivity of a conductor and its electrical resistance given by:
(2)
Where:

Keep in mind that the electrical resistivity of the gold is a known constant which is
and the cross sectional area of the conductor is calculated as:

Because we have a wire in this case, so we assume a cylindrical geometry.
Now replacing our data in (2)

Finally, we know R and V, so replacing these values in (1) we will be able to find the current:

Gravity on the surface of sun is given as

here we know that


now we will have


now we need to find the ratio of weight on surface of sun and on surface of Earth


so weight will increase by 28 times
Radio waves have the longest wavelengths
Answer:

Explanation:
Given:
- charge on the alpha particle,

- mass of the alpha particle,

- strength of a uniform magnetic field,

- radius of the final orbit,

<u>During the motion of a charge the magnetic force and the centripetal forces are balanced:</u>


where:
v = velocity of the alpha particle



Here we observe that the velocity of the aprticle is close to the velocity of light. So the kinetic energy will be relativistic.
<u>We firstly find the relativistic mass as:</u>



now kinetic energy:



If you travel 30 miles somewhere and then come home again your distance is 60 miles. Your displacement is 0 because it is the ending position minus the beginning position, which are the same place (home). In other words, displacement is a vector and distance is a scalar.