Two boys take turns lifting a bucket of water from the well. The first one takes 20 seconds, the second

Two boys take turns lifting a bucket of water from the well. The first one takes 20 seconds, the second one takes 30 seconds. Do they do the same job? Are their capacities the same? Check the answer by calculations, provided that the mass of the bucket with water is 10 kg, the depth of the well is 8 m.

t1 = 20 s.

t2 = 30 s.

g = 10 m / s ^ 2.

m = 10 kg.

h = 8 m.

A1 -?

A2 -?

N1 -?

N2 -?

Mechanical work A is called the product of force F and displacement S: A = F * S. When the bucket is lifted, the force F with which the bucket is pulled will be equal to the gravity of the bucket m * g: F = m * g. Moving will be the depth of the well: S = h.

A = m * g * h.

Since the mass of the bucket with water and the depth of the well are the same, the work of the boys will also be the same: A = A1 = A2 = 10 kg * 10 m / s ^ 2 * 8 m = 800 J.

Power is called the speed of work: N = A / t.

N1 = A1 / t1.

N1 = 800 J / 20 s = 40 W.

N2 = A2 / t2.

N2 = 800 J / 30 s = 26.6 W.

Answer: A1 = A2 = 10 kg * 10 m / s ^ 2 * 8 m = 800 J, N1 = 40 W, N2 = 26.6 W.