Answer:

Explanation:
Given that
d= 1.5 in ( 1 in = 0.0254 m)
d= 0.0381 m
P= 75 hp ( 1 hp = 745.7 W)
P= 55927.5 W
N= 1800 rpm
We know that power P is given as

T=Torque
N=Speed

T=296.85 N.m
The maximum shear stress is given as



We know that 1 MPa =0.145 ksi

To solve this problem we will apply the concepts related to Reyleigh's criteria. Here the resolution of the eye is defined as 1.22 times the wavelength over the diameter of the eye. Mathematically this is,

Here,
D is diameter of the eye


The angle that relates the distance between the lights and the distance to the lamp is given by,

For small angle, 
Here,
d = Distance between lights
L = Distance from eye to lamp
For small angle 
Therefore,



Therefore the distance is 5.367km.
Answer:
On the magnitude of the charges, on their separation and on the sign of the charges
Explanation:
The magnitude of the electric force between two charges is given by

where
k is the Coulomb's constant
q1, q2 are the magnitudes of the two charges
r is the separation between the charges
From the formula, we see that the magnitude of the force depends on the following factors:
- magnitude of the two charges
- separation between the charges
Moreover, the direction of the force depends on the sign of the two charges. In fact:
- if the two charges have same sign, the force is repulsive
- if the two charges have opposite signs, the force is attractive
As momentum / time = force
so; time = 100÷15
so your answer is 6.7 !!