Answer:
1.The velocity of fluid
2.Fluid properties.
3.Projected area of object(geometry of the object).
Explanation:
Drag force:
Drag force is a frictional force which offered by fluid when a object is moving in it.Drag force try to oppose the motion of object when object is moving in a medium.
Drag force given as

So we can say that drag force depends on following properties
1.The velocity of fluid
2.Fluid properties.
3.Projected area of object(geometry of the object).
Answer:
a)Cycle time = 2.37 min
b)Numbers of workers =21
c)Stations on the line =24
Explanation:
Given that
Total work content time(TWC) = 50 min
Production rate Rp= 24 units/hr
manning level will be close =1.5
Line balancing efficiency =0.94
a)
Cycle time


Cycle time = 2.37 min
b)
Numbers of workers ,W


W= 21
Numbers of workers =21
c)
Stations on the line(n)
Lets find service time Ts
Ts = Cycle time - Time for repositioning
Ts = Tc- Tr
Ts= 2.37 - 9/ 60 min
Ts= 2.22 min
We know that efficiency


n=23.94 ⇒n=24
n=24
Stations on the line =24
Answer:
The force between the charges when the separation decreases to 0.7 meters equals 126.955 Newtons
Explanation:
We know that for two point charges of magnitude
the magnitude of force between them is given by

where
is constant
is the separation between the charges
Initially when the charges are separated by 2.4 meters the force can be calculated as

Now when the separation is reduced to 0.7 meters the force is similarly calculated as

Applying value of the constant we get

Thus 
Of course they are needed because without them the society wouldn’t be as nice as it is right now and plus there would be no more buildings ! :)