During world war i, the germans had a gun
called big bertha that was used to shell paris.
the shell had an initial speed of 2.41 km/s at
an initial inclination of 61.5 to the horizontal.
the acceleration of gravity is 9.8 m/s2 .
how far away did the shell hit?
answer in units of km

how long was it in the air?
answer in units of s

Before all let's just convert Km/s into m/s :
             
2.41 km/s = 2410m/s\

To solve the second part
     
First we have to find Vy Vy = 2410 m/s * sin 61.5 = 2410 m/s * 0.8788 =2117.908 m/s.
       
When the shell reaches it's maximum height the vertical velocity component will be zero
 
based on that theorem let's apply linear motion equation
                           
V = u + at
                           
0 = 2117.908 m/s - 9.8 m/S^2 * (t)
                         
t = 216.1130 s
 
As the shell has to go upward and comes back to earth the shell will require a same amount of time in order to reach earth again so the total time that shell will spend on the air will be
                     
2*t = 432.226 s 

I hope my answer has come to your help. Have a nice day ahead and may God bless you always!

Yes, that is the correct formula. to solve this problem given the number of years, plug in the number of years for t and plug the whole thing into the