logo

Crowdly

Browser

Add to Chrome

Questions Bank (1394914 total)

Selecciona los resultados correspondientes a las aproximaciones de las derivadas numéricas en cada versión.

View this question

If the kettle has a power rating of 2000W, how long (in seconds) will it take to boil the kettle?

Does this seem about right?

View this question

How does the energy required to heat the aluminium compare to heating water? Suggest a reason why.

0%
0%
0%
0%
0%
0%
View this question

You put just enough water in your electric kettle to make a cup of tea (raise the temperature from 20°C to 100°C). How much energy, in kJ, does this require?

Assume 1 cup = 250 ml, the density of water is 1 kg/L, and that the heat capacity of water is  4184 J kg-1 K-1

View this question

Calculate the energy required, in kJ, to raise the temperature of a 0.25 kg block of aluminium from 20°C to 100°C.

Take the specific heat capacity of aluminium to be  904 J kg-1 K-1

View this question

What are the SI units of the specific heat capacity?

0%
0%
0%
0%
0%
View this question

What is the main mechanism for heat transfer in the following siutation:

   Using a very bright lamp in a zoo to provide a warm area for animals in their enclosure

0%
0%
0%
View this question

What is the main mechanism for heat transfer in the following siutation:

   Cooling a sports injury by placing an icepack over the bruised area.

100%
0%
0%
View this question

Como é definido “seccionamento” na instalação elétrica?

0%
0%
0%
0%
0%
View this question

Duas esferas idênticas e eletrizadas com cargas elétricas e se atraem com uma força de . Se a carga da primeira esfera aumentar cinco vezes e a carga da segunda esfera for aumentada oito vezes, qual será o valor da força, em newtons, entre elas?

View this question