A stool weighing 2 kg stands on four legs, the footprint of each of which has the shape of a square with a side of 3 cm.

A stool weighing 2 kg stands on four legs, the footprint of each of which has the shape of a square with a side of 3 cm. What is the mass of a cat sitting on a stool if the pressure of the stool together with the cat on the floor is 20 kPa?

To find the mass of a cat on a stool, we will use the formula: P = F / S = m * g / 4S1 = (mt + mk) * g / 4a ^ 2, whence we express: mt + mk = P * 4a ^ 2 / g and mk = P * 4a2 / g – mt.

Variables and constants: P – pressure of the stool and cat on the floor (P = 20 kPa = 20 * 10 ^ 3 Pa); a – the length of the side of the stool leg (a = 3 cm = 0.03 m); g – acceleration due to gravity (g ≈ 10 m / s2); mt is the mass of the stool (mt = 2 kg).

Let’s perform the calculation: mk = P * 4a2 / g – mt = 20 * 10 ^ 3 * 4 * 0.032 / 10 ^ – 2 = 5.2 kg.

Answer: The weight of the cat is 5.2 kg.