The distance traveled by an object in t seconds if its starts at an initial velocity of u m/s and accelerates at a m/s^2 is given by `s = u*t + (1/2)*a*t^2` .
Here u = 50 m/s, a = -10 m/s and t = 1
Substituting these values in the formula for distance traveled:
s = 50*1 - (1/2)*10*1 = 50 - 5 = 45 m
The object is at a distance above the ground equal to 45 m after 1 second.