Acircus acrobat is shot out of a cannon. the equation for the acrobat's pathway can be modeled by h= -16t^2+25. how long will it take him to reach the ground?

For this we almost have the following equation:
 
 We must match the equation to zero:
 
 From here, we clear the value of t.
 We have then:
 
 We discard the negative root because we are looking for time:
 
 
 
 it will take him to reach the ground about:
  seconds

The answer would be -3.9> -4.5