Answer:
Explanation:
If the object is rolling without slipping, every unit of rotated angle equals to a distance perimeter rotated.
Suppose the object complete 1 revolution within time t. The angular distance is 2π rad. Its angular velocity is 2π/t
The distance it covered is its circumference, which is 2πr, and so the speed is 2πr/t
So the linear speed compared to angular speed is
Answer:
force becomes one - ninth
Explanation:
According to Coulomb's law in electrostatics, two charges can exert a force of attraction or repulsion on each other which is directly proportional to the product of two charges and inversely proportional to the square of distance between them.
Here both the charges remains same but the distance is variable.
So, we can say that
.... (1)
Where d be the distance between the tow charges
As the distance between two charges increases by factor of three, let the new force be F'.
.... (2)
Divide equation (2) by equation (1), we get
Thus, the force becomes one - ninth times the initial force.
Answer:
<em>The normal force is perpendicular to the displacement</em>
<em>The static friction force produces no displacement</em>
Explanation:
Work Done By Special Forces
The work is a physical magnitude that measures the dot product of the force applied to an object by the displacement it produces in it.
It can be written in its scalar version as
Being F and d the magnitudes of the force and displacement, and the angle between them
If the angle is zero, the work is at maximum, it the angle is 90°, the work is zero. If the angle is between 90° and 180°, the work is negative.
The normal force acts in the vertical direction when the object is being pushed horizontally. It means the angle between the force and the displacement is 90°, thus the work is
The work is zero because the force and the displacement are perpendicular
The static friction force exists only when the object is being applied a force of a magnitude not large enough to produce movement, i.e. the object is at rest. If the object is moved, the friction force is still present, but it's called dynamic friction force, usually smaller than the static.
Since in this case, there is no displacement, d=0, and the work is