A mass of 50kg rests on a horizontal plane it has a coefficient of friction of 0.64, what is the minimum force needed? Take acceleration due to gravity as 9.81 m/s2.

313.6N

Explanation:

Given parameters;

Mass of the body  = 50kg

Coefficient of friction = 0.64

Acceleration due to gravity  = 9.81m/s²

Unknown:

Minimum force needed to move the body = ?

Solution:

To move this body, the minimum force must overcome the frictional force. So, the value of force that equals to that of the frictional force will set the body in motion.

 Frictional force  = Umg

U is the coefficient of friction

m is the mass

g is the acceleration due to gravity

  Now insert the parameters and solve;

            Frictional force  = 0.64 x 50 x 9.8  = 313.6N

and 1and 1

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day