The third floor of a house is 9 m above the street level. How much work (in kJ) is required to lift a 700-kg piano to the third-story level?
Work reqd.(W)= gain in potential energy
= m*g*h
Solve it to get W in joules
To find the work required to lift a piano to the third-story level, we need to use the formula:
Work = force * distance
First, we need to find the force required to lift the piano. The force can be calculated using the equation:
Force = mass * gravity
where mass is given as 700 kg and gravity is the acceleration due to gravity, approximately 9.8 m/s².
Force = 700 kg * 9.8 m/s² = 6860 N
Now, we have the force required to lift the piano.
Next, we need to calculate the distance. It is given that the third floor of the house is 9 m above the street level.
Distance = 9 m
Finally, we can calculate the work required using the formula:
Work = 6860 N * 9 m
Work = 61740 N·m
To convert the work to kilojoules (kJ), we need to divide by 1000 since 1 kilojoule is equal to 1000 joules.
Work = 61740 N·m / 1000 = 61.74 kJ
Therefore, it would require approximately 61.74 kJ of work to lift the 700 kg piano to the third-story level.