Making a drawing of the system, we will have two forces which are tension and the weight of the object. Balancing the forces present, we do as follows:
T = W
W = 30 N
Therefore, weight is equal to 30 N. Hope this answers the question. Have a nice day. Feel free to ask more questions.
Answer:
Inductance as calculated is 13.12 mH
Solution:
As per the question:
Length of the coil, l = 12 cm = 0.12 m
Diameter, d = 1.7 cm = 0.017 m
No. of turns, N = 235
Now,
Area of cross-section of the wire, A = 
We know that the inductance of the coil is given by the formula:

Answer:
400 N
Explanation:
By the law of friction,

is the maximum frictional force,
is the coefficient of friction and
is the reaction on the refrigerator. On a horizontal surface, the reaction is equal to the weight of the refrigerator.


While not moving, the fricition on the refrigerator is static friction. So, 

This is the maximum frictional force and is more than the applied horizontal force of 400 N. Frictional force cannot be more than the applied force, else it would actually pull the refrigerator backwards (a strange thing, if it were to happen). It is equal to the extent of the applied force because the applied force is not enough to overcome the maximum.
Hence the frictional force is 400 N.
PS: Note that we do not use the coefficient of kinetic friction because applied force could not overcome the static friction.
Think of the formula force=mass x acceleration. even though they have the same acceleration, a train has more mass. is that helpful?
Answer:
A & B
Explanation:
A & B Would be the right answer since Morse code cannot be represented through the height of the fire.