To solve the exercise it is necessary to apply the equations necessary to apply Newton's second law and the concept related to frictional force.
An angle of 30 degrees is formed on the vertical at an applied force of 2.3N
In this way the frictional force, opposite to the movement will be given by
where,
Kinetic friction constant
N = Normal Force (Mass*gravity)
The friction force is completely vertical and opposes the rising force of 2.3 N. The Normal force acts perpendicular to the surface (vertical) therefore corresponds to the horizontal component of the applied force.
The ascending force would be given by
As the block is moving upward, the friction force acts downward, also its weight acts downward. We can have
Considering the horizontal force the normal force on the block must be balanced by the horizontal component of pishing foce
Then the frictional force
Therefore the coefficient of kinetic friction is 0.26
Answer:
Option C ⇒ D=2λr is the correct answer, since it has the largest aperture diameter.
Explanation:
Regarding Rayleigh's criterion, the angular resolution is given as below:
θ = 1.22λ/D
From this expression, it is observed that the larger the aperture size, the smaller will be the value of the angular resolution, and the better the device will be.
This signifies that at very high angular differences, the precision for distinguishing two points is high.
Therefore, option C ⇒ D=2λr is the correct answer, since it has the largest aperture diameter.
The needle has buoyancy and that means it won't sink. It also has a lot to do with the weight of the needle which is very little. The less weight there is the easier it will be to float.
power = (voltage) x (current)
17 w = (5 v) x (current)
current = (17 w) / (5 v) = 3.4 Amperes