how much does a car weighr if each tyre cover of 4cm^2 and exert a pressure of 100000Nm^-2 on the ground it is physics questions ​

Weight = 160 N

Explanation:

The weight of an object is a measure of the gravitational force on the object. So that weight is synonymous to the force applied by the object.

i.e Weight = mass x gravitational force

Also, the pressure of an object is the ratio of its force to area covered by the object. So that;

P =

Given that: area = 4 (0.0004 ), and pressure = 100 000 N.

Then;

F = PA

  = 100 000 N x 0.0004

F = 40 N

The force applied on the ground by each of the four tyres of the car is 40 N.

Thus, the weight of the car = 4 x 40 N

                                     = 160 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