Answer:
1.24
Explanation:
The resistivity of copper
The resistivity of Aluminum,
The wires have same resistance per unit length.
The resistance of a wire is given by :
According to given condition,
So, the required ratio of the diameter of Aluminum to Copper wire is 1.24.
To determine the Force it is necessary that Samantha starts from the consideration of the dynamic balance between the forces acting on the car. For this, the centripetal force must be equal to the friction force (otherwise the car would lose contact with the ground), the expression of these two forces would be
Here,
= Coefficient of kinematic friction
m = mass
g = Acceleration due to gravity
v = Velocity
r = Radius
From this relationship then she should assume the following
1) The car travels at a constant speed
2) There is indeed that frictional force between the car and the road
3) There is no loss of mass during displacement
4) The centripetal force must be equal to the frictional force so that the car does not lose contact or slip
5) The radius must be constant
Answer:
, attractive.
Explanation:
For calculating this force we use the Coulomb Law:
Where is the Coulomb's constant,
and
the values of each charge and r the distance between them.
Since the Coulomb's constant as I wrote it is in S.I. we have to write all the magnitudes in that system of units, and substitute:
This force is attractive since both charges are of opposite sign.