Logan observes a paramecium under a microscope. the eyepiece of the microscope has a horizontal scale marked in mm. the paramecium starts at the 65 mm mark and ends up at the 39 mm mark.
what is the paramecium's displacement? express your answer with appropriate units.

d =  -26 mm

Explanation:

given,

initial position of paramecium, x = 65 mm

final position of paramecium, y = 39 mm

displacement of the paramecium's = ?

displacement  = final position - initial position

 d =  y - x                      

d = 39 - 65                

d =  -26 mm              

The paramecium's displacement comes out to be -26 mm

Newton states: F=G*M*m/ r^2, where M= ρ* (4/3)*pi*r^3 is mass of iron planet, r is radius of the planet; 
 the same gravity force F=m*w^2*r is the centripetal force for the orbiting satellite, where angular speed w=2pi/T, T is period; 
 thus F=F; G*M*m/ r^2 = m*w^2*r; or; 
G*(ρ* (4/3)*pi*r^3)/ r^2 = (2pi/T)^2*r; or; 
G*ρ/3 = pi/T^2, hence T= √(3pi/(G*ρ)) = 
= √(3pi/(6.6742E-11 *7860)) =4238.62s = 70h 38’;