Answer:
18 miles
Explanation:
The average speed is 6 mph
Melanie ran for 3 hours
Speed × Time = Distance
So, 6 mph × 3 h = 18 miles
 
        
             
        
        
        
Because of the law of inertia and it’s effect on the skater
        
             
        
        
        
Answers:
a) 
b) 
Explanation:
a) Since we are told the satellites circle the space station at constant speed, we can assume they follow a uniform circular motion and their tangential speeds  are given by:
 are given by:
 (1)
 (1)
Where:
 is the angular frequency
 is the angular frequency
 is the radius of the orbit of each satellite
 is the radius of the orbit of each satellite
 is the period of the orbit of each satellite
 is the period of the orbit of each satellite
Isolating  :
:
 (2)
 (2)
Applying this equation to each satellite:
 (3)
 (3)
 (4)
 (4)
 (5)
 (5)
 (6)
 (6)
 (7)
 (7)
 (8)
 (8)
Ordering this periods from largest to smallest:

b) Acceleration  is defined as the variation of velocity in time:
 is defined as the variation of velocity in time:
 (9)
 (9)
Applying this equation to each satellite:
 (10)
 (10)
 (11)
 (11)
 (12)
 (12)
 (13)
 (13)
 (14)
 (14)
 (15)
 (15)
Ordering this acceerations from largest to smallest:

 
        
             
        
        
        
2 min = 120 sec 
120/15 = 8 
The black horse represents 8 seconds.
        
                    
             
        
        
        
Options A and D are correct. The strength of the force of friction depends on the objects' sizes and weights and the heat generated by the friction and the types of surfaces involved.
<h3 /><h3>What is the friction force?</h3>
It is a type of opposition force acting on the surface of the body that tries to oppose the motion of the body. its unit is Newton (N). 
Mathematically, it is defined as the product of the coefficient of friction and normal reaction.
On resolving the given force and acceleration in the different components and balancing the equation gets. Components in the x-direction.
The strength of the force of friction depends on the two factors, as;
A. The objects' sizes and weights.
D. The heat generated by the friction and the types of surfaces involved.
Hence, options A and D are correct.
To learn more about the friction force, refer to the link;
brainly.com/question/1714663
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