Answer: 
Explanation:
Given
Mass of child 
speed of child is 
Moment of inertia of merry go round is 
radius 
Conserving the angular momentum

Answer:
An electric fan is considered to be a mixture of several simple machines. It includes the Wheel and Axle type, wedges, and the Inclined plane types. The blades of an electric fan are the inclined planes and the wedges.
Answer:
» e. Electrons and protons
Explaination :
Electrons are negatively charged and protons are positively charged.
- The neutrons do not have a charge.
Given :
An electron moving in the positive x direction experiences a magnetic force in the positive z direction.
To Find :
The direction of the magnetic field.
Solution :
We know, force is given by :

Here, q = -e.

Now, for above condition to satisfy :

So, 
Therefore, direction of magnetic field is negative y direction.
Hence, this is the required solution.
It's called the <span>Principle of Original Horizontality
</span><span> it just </span>means<span> what it sounds like: that all </span>rock layers <span>were originally horizontal.
</span>Of course, it only applies to sedimentary rocks<span>.
</span>Recall that sedimentary rock is composed of <span> sediments, which are deposited and compacted in one place over time.</span>