Answer:
Explanation:
Given
Distance to grandmother's house=100 mi
it is given that during return trip Julie spend equal time driving with speed 30 mph and 70 mph
Let Julie travel x mi with 30 mph and 100-x with 70 mph

x=30 mi
Therefore
Julie's Average speed on the way to Grandmother's house
=42 mph
On return trip

Answer:Technician A
Explanation:
Technician A statement is correct as
The battery is required to start the vehicle which, in effect, rotates the alternator at sufficient speed to keep the battery charged. This means if the battery is low it is not possible to start the vehicle and thus we are unable to test the alternator.
That is the battery is pre-requisite to test the alternator. So the battery must be at least a 75 % charge to test the alternator.
To develop the problem it is necessary to apply the equations related to the moment of inertia.
The given values can be defined as,




According to the definition of the moment of inertia applied to the exercise we can arrive at the equation that,

Where n is the number of spokes necessary to construct the wheel.


Replacing the values at the general equation we have,

Solving for n,

Therefore the number of spokes necessary to construct the wheel is 36
PART B) The mass of the wheel is given by the sum of all masses and the total spokes, then



Therefore the mass of the wheel must be of 1.36Kg