What is the current flowing through the 1.6 ohm resistance in the circuit?

here we need to find the net equivalent resistance of whole circuit

in order to find this

3 ohm and 2 ohm in first branch in parallel

now this combination of 2 ohm and 3 ohm is in series with 0.8 ohm

so this combination is equivalent as

now this 2 ohm and 0.5 ohm is in parallel

so we will have

now this whole is in series with 1.6 ohm

now we can use ohm's law

now we have current in the circuit as

pe = weightxheight = 2000x1000=2,000,000joules