A team of dogs, dragging the sled along a horizontal path of 5 km long, performs 400 kJ of work.

A team of dogs, dragging the sled along a horizontal path of 5 km long, performs 400 kJ of work. Assuming that the friction coefficient is 0.02, find the mass of the sleigh.

The given problems: S (the length of the path covered by the team of dogs) = 5 km (in SI S = 5000 m); A (perfect team work) = 400 kJ (400 * 10 ^ 3 J); μ (coefficient of friction) = 0.02.

Reference values: g (acceleration due to gravity) ≈ 10 m / s2.

We express the mass of the sleigh from the formula: A = Ftr * S = μ * N * S = μ * m * g * S, whence m = A / (μ * g * S).

Let’s make a calculation: m = 400 * 10 ^ 3 / (0.02 * 10 * 5000) = 400 kg.

Answer: The required weight of the sleigh is 400 kilograms.