Answer :
Answer:
We conclude that the physicists can change the temperature 20 hours.
Step-by-step explanation:
We know that a physicist must make sure that the temperature of metal at 0° C gets no colder than -80° C. The physicist changes the metal's temperature at a steady rate of -4° C per hour. We calculate how long can the physicists change the temperature. We get:
[tex]t=\frac{-80-0}{-4}=\frac{80}{4}=20[/tex]
We conclude that the physicists can change the temperature 20 hours.