A mechanic replaces a worn out engine of a car with a new, more efficient. The old engine had a useful output power 52kW and and efficiency of 25%. The new engine has an efficiency of 30%. Calculate the useful output power of the new engine.
You can assume that the input power of both engine is the same

Diego is trying to lift a piano to the second floor of his house. diego uses a pulley system and gives a big lift to the piano. the piano moves upward, then stops, and then it starts to fall to the ground. which list best describes the forces on the piano in the proper order? a.positive force, balanced force, negative force b.negative force, balanced force, positive force c.positive force, unbalanced force, negative force d. negative force, unbalanced force, positive force