A 80 N horizontal force is applied to a 20.0 kg block at rest on a horizontal surface where µS = 0.6.? What is the magnitude of the force of friction on the block?

The frictional force on the block is 118 N.

Explanation:

Given;

horizontal force applied on the block, f = 80 N

mass of the block, m = 20.0 kg

coefficient of friction, μ = 0.6

The frictional force on the block is calculated as;

F = μR

F = μ(mg)

F = 0.6(20 x 9.81)

F = 117.7 N

F = 118 N.

Therefore, the frictional force on the block is 118 N.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)