Answer:
It will take 4 minutes and 30 seconds for hot coffee to cool to a temperature of 25 ° C
Step-by-step explanation:
This problem can be modeled by a first order equation
T(t) = TA + kt
In which TA is the temperature at instant zero and r is the rate of warming(g>0) or cooling(k<0). t is the time in minutes.
The initial temperature of the cup of coffee is 70ºC. So TA = 70. The temperature cools at the rate of 10ºC per minute, so k = -10. So, the equation of the model is:
T(t) = 70 - 10t
We want to know the instant of time when T = 25, so:
25 = 70 - 10t
10t = 70 - 25
10t = 45
t = 4.5 minutes
It will take 4 minutes and 30 seconds for hot coffee to cool to a temperature of 25 ° C
Answer:
cheese
Step-by-step explanation:
Answer:
120 units^2
Step-by-step explanation:
(12)(5)(0.5)(2) + (12)(2) + (13)(2) + (5)(2) = 120 units^2
Answer:
The equations have the same mathematical form:
S = A + V0 t - 1/2 g t^2
They are both quadratic equations in one variable (t here)
This equation expresses the distance traveled by an object in time t in the vertical direction - it does not necessarily refer to a graph
In the other equation, y can be considered a vertical coordinate equation on a graph and x would be the horizontal coordinate
Note that in one equation 3 terms are necessary to describe the displacement of an object in one direction
In the other 2 terms in the x-direction describe the displacement in the other or y-direction
8. 240/3 = 80 km per hour
80*4 = 320 km answer is A
9.
5.25 / 3 = 1.75 per kg answer is A.
