To solve this problem we will use the related concepts in Newtonian laws that describe the force of gravitational attraction. We will use the given value and then we will obtain the proportion of the new force depending on the Radius. From there we will observe how much the force of attraction increases in the new distance.
Planet gravitational force
Distance between planet and star
Gravitational force is
Applying the new distance,
Replacing with the previous force,
Replacing our values
Therefore the magnitude of the force on the star due to the planet is 
Answer: a.) Roughness of the surfaces in contact with each other .
Higher the roughness of surfaces in contact with each other, greater is the friction between bodies. Force of friction will be less between smooth surfaces.
b.) Weight of the sliding/rolling body: greater the weight of the moving body on the surface, more is the force of friction on the body by the surface.
I hope this helps
Answer with Explanation:
We are given that
Diameter=0.030 m
Length of sprue=
=0.200 m
Metal volume flow rate,Q=0.03
Q=
because 1 minute=60 seconds
Let 1 for the top and 2 for the bottom
Pressure at the top and bottom of the sprue is atmospheric
Substitute the values
Reynolds number=
Substitute the values then we get
Reynolds number=
Reynolds number=42525
The Reynolds number is greater than 4000 .Therefore, the flow is turbulent.
So that international people don't mistake units for others. ex 1 inch could be mistaken for 1 cm in non American countries
