Find the power that a person develops by lifting a 12kg bucket of water. from a well with a depth of 10m for a time of 15sec.

Power is a physical quantity, equal to the work that is performed per unit of time, that is

N = A / t.

where A is the work, t is the time during which the work was performed.

In general, work is determined by the formula:

A = F * S,

where F is the force applied to the body, S is the path traversed by the body under the action of the force F.

Taking these two formulas into account, we obtain

N = F * S / t.

Since the work is done against gravity, then F = m * g,

where m is the mass of a bucket with water, g = 9.82 (m / s2) ≈ 10 (m / s2) is the acceleration of gravity.

Taking into account the above, the formula for the power can be written:

N = m * g * S / t.

Let’s make the calculations:

N = m * g * S / t = 12 * 10 * 10/15 = 0.8 * 100 = 80 (W).

Answer: N = 80 (W).