3. if a car's wheels are replaced with wheels of greater diameter, will the reading of the speedometer change? explain.

YES

Explanation:

The speedometer converts revolutions to a linear distance based on an assumption that the car uses wheels of standard radius. If the radius were to be increased significantly, then the speedometer would significantly underestimate the speed of the car.

It is necessary to be at 2.66 Earth radii to experience an acceleration of  .  

Explanation:          

The height above the earth surface necessary to experience an acceleration of can be found by means of the Universal law of gravity:

 (1)

Then, replacing Newton's second law in equation 3 it is gotten:

 (2)

Then, r can be isolated from equation 2    

 (3)

Where G is the gravitational constant, M is the mass of the Earth and a is the acceleration.                

Hence, it is necessary to be at 2.66 Earth radii to experience an acceleration of  .