At room temperature of 30 degree celsius, a glass of water takes one minute to cool from 80 degree celsius to 60 degree Celsius. How long will it take to further cool from 60 degree celsius to 50 degree celsius?

Well from 80 to 70 to 60 is three twenty seconds. 20+20+20=100 (one minute) so from 60 to 50 is 20 seconds. Answer: It will take 20 seconds to cool from 60 degree Celsius to 50 degree Celsius.

newtons law of cooling applies:

http://www.softschools.com/formulas/physics/newtons_law_of_cooling_formula/93/

from the data of room temp, 80 to 60, determine rate r.
then put that in the formula to figure time from 60 to 50.

If you need help with this calculation, ask.

thank you bobpursley

To determine how long it will take for the glass of water to cool from 60 degrees Celsius to 50 degrees Celsius, we can make use of the Newton's law of cooling equation.

Newton's law of cooling states that the rate of change of the temperature of an object is proportional to the difference between its current temperature and the surrounding temperature. It can be expressed as:

ΔT/Δt = -k(T - Ts)

Where:
ΔT/Δt is the rate of change of temperature (change in temperature over change in time),
k is the constant of proportionality,
T is the current temperature of the object, and
Ts is the surrounding temperature.

In this case, let's assume that the surrounding temperature (Ts) remains constant at 30 degrees Celsius.

We know that when the water cools from 80 degrees Celsius to 60 degrees Celsius, it takes one minute. We can use this information to find the value of the constant of proportionality, k.

ΔT/Δt = -k(T - Ts)
(60 - 80)/(1) = -k(80 - 30)
-20 = -k(50)
-20/50 = -k
-2/5 = k

Now that we know the value of k, we can use it to find the time it takes for the water to cool from 60 degrees Celsius to 50 degrees Celsius.

ΔT/Δt = -k(T - Ts)
(50 - 60)/(Δt) = -(-2/5)(60 - 30)
-10/(Δt) = -2/5(30)
-10/(Δt) = -2/5(30)
-10/(Δt) = -60/5
-10/(Δt) = -12
Δt/10 = 1/-12
Δt = -10/-12
Δt = 10/12
Δt = 5/6

Therefore, it will take 5/6 minutes (or 50 seconds) for the glass of water to further cool from 60 degrees Celsius to 50 degrees Celsius at a room temperature of 30 degrees Celsius.