Answer is C is the correct answer
Answer:
the final temperature = 74.33°C
Explanation:
Using the expression Q = mcΔT for the heat transfer and the change in temperature .
Here ;
Q = heat transfer
m = mass of substance
c = specific heat
ΔT = the change in temperature
The heat Q required to change the phase of a sample mass m is:
Q = m
where;
is the latent heat of vaporization.
From the question ;
Let M represent the mass of the coffee that remains after evaporation is:
ΔT = 
where;
m = 2.50 g
M = (240 - 2.50) g = 237.5 g
= 539 kcal/kg
c = 1.00kcal/kg. °C
ΔT = 
ΔT = 5.67°C
The final temperature of the coffee is:
ΔT
where ;
= initial temperature = 80 °C
= (80 - 5.67)°C
= 74.33°C
Thus; the final temperature = 74.33°C
Answer:
1 minute 36.85 seconds
Explanation:
First we need to convert the miles into meters, as the demanded result should be in meters.
1 mile = 1,609.34 meters
Also, 6.5 minutes should be converted into seconds.
1 minute = 60 seconds
6.5 x 60 = 390 seconds
Now we need to divide the miles with the seconds to see how much meters have been run in a second.
1,609.34 / 390 = 4.13 meters
The suggested meters now should be divided with the distance run in one second.
400 / 4.13 = 96.85 seconds
So we get a result of 96.85 seconds, or 1 minute 36.85 seconds.
Answer:

Explanation:
Given


Required
Determine the speed of B w.r.t A
The question implies that, we determine the relative velocity of B w.r.t A
Because both trains are moving towards one another, the required velocity is a
both trains:
This is shown below:


