What work on lifting a barbell with a mass of m = 200kg to a height of h = 2.00m did the strength

What work on lifting a barbell with a mass of m = 200kg to a height of h = 2.00m did the strength of the weightlifter’s muscles? What is the work of the force of gravity acting on the barbell?

Data: m (rod weight) = 200 kg; h (height the boom was lifted) = 2 m.

Reference data: according to the condition g (gravitational acceleration) = 10 m / s2.

1) The strength of the muscles of the weightlifter: F = m * g = -Ft (gravity).

2) The vector of movement of the bar is directed upwards, so the work of the muscles of the weightlifter is positive, and the work of gravity is negative: A = -At = m * g * h = 200 * 10 * 2 = 4000 J (4 kJ).

Answer: The strength of the muscles of the weightlifter has done work of 4 kJ, the work of gravity is -4 kJ.