Answer:
Work done to pull the piano upwards is 401250 J
Explanation:
Work is done against the gravity to pull the piano upwards
So here we can say that work done is

here we know that

also we know that
H = 75 m
now we have


Answer:
6 voltage is applied by the batteries.
Explanation:
To solve this sort of problem involving current, resistance and voltage, we use the relation:<em> </em><em>Voltage</em><em>= </em><em>Current x Resistance</em>.
From the problem, the following have been given:
Resistance= 2.4 ohms.
Current= 2.5 amps.
Required: Voltage?
Fix the values of current and resistance into the relation:
Voltage= <em>2.5 x 2.4</em>
=6 volts.