The time taken by the rock will be 8.77 seconds.
<h3>What is speed?</h3>
Speed is defined as the ratio of the time distance traveled by the body to the time taken by the body to cover the distance.
Given that:-
The equation for free fall at the surface of some planet (s in meters, t in seconds) is s = 2.86t²
The time will be calculated by using the speed formula.
Speed = Distance \ Time 
25.1   = 2.86t² \ t
t   =  25.1 / 2.86
t   =  8.77 seconds
Therefore the time taken by the rock will be 8.77 seconds.
To know more about Speed follow
brainly.com/question/6504879
#SPJ1
 
        
             
        
        
        
It’s 54 because I did the math to get the answer
        
             
        
        
        
AA , BB , and CC are parallel to MN.