A box has a mass of 4kg and surface area 4m². Calculate the pressure exerted by the box on the floor.
​

Asmall metal bar, whose initial temperature was 10° c, is dropped into a large container of boiling water. how long will it take the bar to reach 70° c if it is known that its temperature increases 2° during the first second? (the boiling temperature for water is 100° c. round your answer to one decimal place.) sec how long will it take the bar to reach 98° c? (round your answer to one decimal place.)

Um vetor representa um deslocamento cujo módulo é 20 m. se v faz um ângulo de 60 graus com a horizontal, qual é o valor das componentes horizontal e vertical deste vetor?

A90db sound wave strikes an eardrum whose area is 5.0×10^-5m^2. how much energy is absorbed by the eardrum per second