Answer:
Orbital period, T = 1.00074 years
Explanation:
It is given that,
Orbital radius of a solar system planet, 
The orbital period of the planet can be calculated using third law of Kepler's. It is as follows :

M is the mass of the sun
 
    

T = 31559467.6761 s
T = 1.00074 years
So, a solar-system planet that has an orbital radius of 4 AU would have an orbital period of about 1.00074 years.
 
        
             
        
        
        
Answer and Explanation:
You don't have water because of two possible reasons:
- Because of the summer and the little rain, the underwater supply goes low.
- The slope in the hill you live makes the underground water goes down by the effect of gravity. Imagine the underground water like a small tank, when the water is reduced for any reason the bottom of the tank will have the remaining water, while the top part will be "empty".
 
        
             
        
        
        
Car A take a time of 2.55hr and car B take a time of 2.14 hr
We know that distance divide by time is speed 
here it is given that car A to reach a gas station a distance 189 km from the school traveling at a speed of 74 km/hr
so speed=distance/time
s=d/t
t=d/s
=189/74
=2.55hr
In case of car B it is given that The distance from the is 199.8km, car b is traveling at a speed of 93 km/hr  
s=d/t
t=d/s
=199.8/93
=2.14hr  
so from the above given data and the formula we solved and found out the time taken by car A is 2.55h and car B is 2.14h
learn more about Speed here brainly.com/question/13943409
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