Complete question is;
When you ride a bicycle, in what direction is the angular velocity of the wheels? A) to your left B) to your right C) forwards D) backwards
Answer:
Option A - to your left
Explanation:
While an object rotates, each particle will have a different velocity:
the 'Speed' component will vary with radius while the 'Direction' component will vary with angle.
All of the velocity vectors are aligned in the same plane.
We can be solve this by choosing a single vector normal to ALL of the possible velocity vectors of the rotating object in that plane.
This convention used is known as "Right-hand rule". The angular velocity vector points along the wheel's axle. For instance, if you Imagine wrapping your right hand around the axle so that your fingers point in the direction of rotation, with your thumb sticking out. You will notice that your thumb points to the left.
Thus;
By right-hand rule, a wheel rotating on a forward - moving bicycle has an angular velocity vector pointing to the rider's left.
So, option A is the correct answer
Strong Nuclear force: it is the short range force and strongest fundamental force in all type of forces.
Electromagnetism: this is the force due to magnetic and electric behavior of the particles. It is moderate type of force and its range is more than Nuclear force.
Weak Nuclear Force: This force is also short range force which act between the nucleoside. But this force is also moderate type of force
Gravitational force: this force is between two point masses and least order of force. also the range of this force is upto infinite.
so the correct order of this fundamental force is
<em>strong nuclear, electromagnetism, weak nuclear, gravitational</em>
Answer: C) The two particles will move away from each other
Explanation:
When two electrically charged bodies come closer, appears a force that attracts or repels them, depending on the sign of the charges of this two bodies.
This is stated by Coulomb's Law:
"The electrostatic force 
between two point charges 
and 
is proportional to the product of the charges and inversely proportional to the square of the distance 
that separates them, and has the direction of the line that joins them"
Mathematically this law is written as:
Where 
is a proportionality constant.
Now, if and have the same sign charge (both positive or both negative), a repulsive force will act on these charges.
