Answer: Physical
Explanation: There are no changes being done to the salt. Think of it this way, if you dissolve the salt in water then boil the water completely, you will have the same salt you started with.
The resistance of a given conductor depends on its electrical resistivity (
), its length(L) and its cross-sectional area (A), as follows:

In this case, we have
,
and
. So, the total resistance of the wire with length of 138m is:

Answer:
The bullet's initial speed is 243.21 m/s.
Explanation:
Given that,
Mass of the bullet, 
Mass of the pendulum, 
The center of mass of the pendulum rises a vertical distance of 10 cm.
We need to find the bullet's initial speed if it is assumed that the bullet remains embedded in the pendulum. Let it is v. In this case, the energy of the system remains conserved. The kinetic energy of the bullet gets converted to potential energy for the whole system. So,
V is the speed of the bullet and pendulum at the time of collision
Now using conservation of momentum as :
Put the value of V from equation (1) in above equation as :

So, the bullet's initial speed is 243.21 m/s.
Answer:

Explanation:
It is given that,
Length of the wire, L = 0.6 m
Current flowing inside the wire, I = 2 A
Uniform magnetic field, B = 0.3 T
Force experienced by the wire in the magnetic field, F = 0.18 N
To find,
The angle made by the wire with the magnetic field.
Solve,
We know that the magnetic force acting on the wire inside the magnetic field is given by :




Therefore, the wire makes an angle of 30 degrees with respect to magnetic field.
Answer:
D.
For every action there is an equal and opposite reaction.
Explanation:
im doing the same one lol