Answer:
31.9 m
Step-by-step explanation:
First of all, let's start by calculating the mass of the object, which is given by

where
W = 7000 N is the weight
g = 9.8 m/s^2 is the acceleration of gravity
Substituting,

Now, we want this object to have the same energy as its kinetic energy when it travels at

So when its kinetic energy is

The gravitational potential energy is given by

where h is the heigth of the object. We want the object to have the same energy as calculated for K, so we write
U = K
and solving for h, we find
