During a chemical reaction, the temperature in a beaker decreased every minute by the same number of degrees. The temperature was 63degreesF at 11:30 a. m. By 11:54 a. m., the temperature had dropped to minus12degreesF. By how many degrees did it change each minute?

The answer to your question is "The temperature drops 3.125°F each minute".

Explanation:

Data

Initial temperature = 63°F          Initial time = 11:30 am

Final temperature = -12°F           Final time = 11:54 am

Process

1.- Calculate the difference of minutes

    11:54 - 11:30 = 24 min

2.- Calculate the difference of temperature

    63°F - (-12°F) = 63°F + 12°F = 75°F

3.- Divide the difference of temperature by the difference of time

                75/24 = 3.125

4.- Conclusion

   The temperature drops 3.125°F each minute.

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.