(Originais Teachy 2023) - Question Medium of Physics

Beverages can be chilled more quickly using styrofoam boxes containing ice and a little commercial coarse salt. In this process, the ice melts with consequent formation of liquid and cooling of the beverages. An erroneous interpretation, based on common sense, relates this effect to the great ability of coarse salt to remove heat from the ice. From a scientific point of view, rapid cooling occurs due to more efficient heat transfer between the ice, salt, and beverages.

A student is observing an object through a converging lens with a focal length of 10 cm. The object is located 40 cm away from the lens. (Consider that the thin lens approximation is valid). Based on this information: 1) Calculate the position of the image formed by the lens. 2) Determine the size of the image relative to the size of the object, knowing that the lens obeys the Gauss equation (1/f = 1/p + 1/p'), where f is the focal distance of the lens, p is the distance from the object to the lens, and p' is the distance from the image to the lens, all measured in cm. Consider that the coordinate system used has its origin at the lens's optical center, with the main axis oriented positively to the right, and that real images have a positive sign and virtual images have a negative sign.

João is helping his father fill the home pool, which is rectangular and has the following dimensions: 8 meters in length, 4 meters in width, and 1.5 meters in depth. They are using a hose with a constant flow rate of 20 liters per minute. Considering that the pool was completely empty and there was no water wastage in the process, answer: (a) What is the total volume of the pool in liters? (b) How long, in hours, will it take to completely fill the pool with the hose? (c) If the water in the pool had the mentioned constant flow rate, but drained through an opening of the same size as the hose, how long would it take for the pool to completely empty?

An isovolumetric transformation is a chemical process in which the volume of a system is kept constant. In this process, the internal energy of the system can be changed through the transfer of heat between the system and the external environment. Which of the following statements is correct?