Hello!
Answer: 7918 J
Explanation:
We are assuming that the floor (field) is completely horizontal since there's no information about that in the statement.
We are going to use the following formula:

Where:


º

Then, by substituting we have:

Answer:
∆PE = 749.7 J
At 0.9 m high, PE = 793.8 J
At 1.75 m high, PE = 1543.5 J
The potential energy decreases while the kinetic energy increases.