Answer:
Using the kinematic equation:
h = 1/2 * g * t^2
where h is the initial height (80m), g is the acceleration due to gravity (-10 m/s^2), and t is the time it takes to reach the ground, we can solve for t:
t = sqrt(2h/g)
t = sqrt(2(80m)/10m/s^2)
t = 8 seconds
Therefore, it takes 8 seconds for the body to reach the ground.