(Originais Teachy 2023) - Question Medium of Physics

A person with height $$\boldsymbol{h}$$ stands in front of a pinhole camera in order to produce an image on the opposite side of the camera that corresponds to three quarters $$(3 / 4)$$ of their height. Knowing that the pinhole camera has a depth $$\boldsymbol{d}$$, what will be the distance between the person and their image?

A motor operates according to the Carnot cycle between two thermal sources. The hot source is at a temperature of 500 K and the cold source at 300 K. Determine the efficiency of the motor, knowing that the efficiency of the Carnot cycle is calculated by the expression 1 - (Tcold/Thot), where Tcold and Thot are the temperatures of the cold and hot sources, respectively. Discuss briefly the importance of the maximum efficiency of the Carnot cycle in practical applications of thermal engines.

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 electric car was developed to be a more sustainable alternative to combustion cars, which use non-renewable resources. This car travels in a straight line, starting from an initial position of 20 meters and reaching a final position of 120 meters. Calculate the position variation (Δx) of this car during the journey.