Answer:
Explanation:
Given

angular velocity 
Combined moment of inertia of stool,student and bricks 
Now student pull off his hands so as to increase its speed to suppose
rev/s
After Pulling off hands so final moment of inertia is

Conserving angular momentum as no external torque is applied




Answer:
They can use it for when they are dormant in the winter or to grow more sources for storing and creating energy, or they store the energy (this energy would be considered stored energy).
Answer:
The fundamental frequency of can is 2.7 kHz.
Explanation:
Given that,
A typical length for the auditory canal in an adult is about 3.1 cm, l = 3.1 cm
The speed of sound is, v = 336 m/s
We need to find the fundamental frequency of the canal. For a tube open at only one end, the fundamental frequency is given by :

So, the fundamental frequency of can is 2.7 kHz. Hence, this is the required solution.
Well, since you only want direction, ignore the numbers. Use the right hand rule.
Current (pointer finger) points west (left).
Magnetic field (middle finger) points south (towards you).
Force (thumb) then points up (away from the earth)