Answer:
<h3>The answer is 8.5 kg</h3>
Explanation:
The mass of the object can be found by using the formula

where
f is the force
a is the acceleration
So we have

We have the final answer as
<h3>8.5 kg</h3>
Hope this helps you
Formula for potential energy is V=mgh, where m is mass in KG, g is earth acceleration (10 m/s^2), and h its height in meters. We know mass, acceleration is constant and also known, we know height also. Lets substitute
V=75*10*300=225000[J]=225[kJ] - its the answer