Answer:
mu = 0.56
Explanation:
The friction force is calculated by taking into account the deceleration of the car in 25m. This can be calculated by using the following formula:

v: final speed = 0m/s (the car stops)
v_o: initial speed in the interval of interest = 60km/h
= 60(1000m)/(3600s) = 16.66m/s
x: distance = 25m
BY doing a the subject of the formula and replace the values of v, v_o and x you obtain:

with this value of a you calculate the friction force that makes this deceleration over the car. By using the Newton second's Law you obtain:

Furthermore, you use the relation between the friction force and the friction coefficient:

hence, the friction coefficient is 0.56
Yes, for balance.hope this helped.
Answer:
They move farther apart
Explanation:
When objects heat up they expand for example heating up a balloon makes it expand
Well I can't see the following physical properties you talked about in the question.
Mass per unit volume ratio is called density.
Newton's second law states that F=ma so that means force =mass×acceleration force and mass