To solve this problem it is only necessary to apply the kinematic equations of angular motion description, for this purpose we know by definition that,
Where,
Angular Displacement
Angular Acceleration
Angular velocity
Initial angular displacement
For this case we have neither angular velocity nor initial angular displacement, then
Re-arrange for 
Replacing our values,
Therefore the ANgular acceleration of the mass is 
Where is the picture cant6 see it
Answer:
Number of turns per unit length will be 
Explanation:
We have given that strength of the magnetic field produced by the solenoid B = 7 T
Current in the solenoid i = 200 A
Let the number of turns per unit length is n
Magnetic field due to solenoid is given as 
here 
is permeability of free space n is number of turns per unit length and i is current
So 
To measure the strength of an earthquake, you can use either a Richter scale or Mercalli scale. Richter scale uses the amplitued of the wave and the distance from the source. Mercalli scale uses observations of people and is not considered to be scientific as Richter scale.
Answer:reflection by dust particles in air
