Answer:
Acceleration stress, physiological changes that occur in the human body in motion as a result of rapid increase of speed. ... A force of 3 g, for example, is equivalent to an acceleration three times that of a body falling near Earth.
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:
When there is nearsightedness or myopia
Explanation:
As, in myopia the image is formed in front of the retina.
Which makes things looking at things near very easy, but looking at far away things very difficult.
So concave lens makes things look bigger, so therefore, it is used during myopia, to make things look bigger when they are far away
Answer:
Approximately
(given that the magnitude of this charge is
.)
Explanation:
If a charge of magnitude
is placed in an electric field of magnitude
, the magnitude of the electrostatic force on that charge would be
.
The magnitude of this charge is
. Apply the unit conversion
:
.
An electric field of magnitude
would exert on this charge a force with a magnitude of:
.
Note that the electric charge in this question is negative. Hence, electrostatic force on this charge would be opposite in direction to the the electric field. Since the electric field points due south, the electrostatic force on this charge would point due north.