A dog is running at 9.1 m/s for 7.8 km. How long did it take him to arrive at his destination? (Give answer in seconds)
Have you never heard of the equation
D = V t, or
(distance) = (speed) x (time)?
From that, you can derive
t = D/V
Convert the distance D = 7800 m and use the equation above.
t = 7800/9.1 = ___ s