Answer: A
Explanation:
Isotopes of different elements differ by the number of neutrons inside the nucleus.
Answer:
Average speed of the car A = 70 miles per hour
Average speed of the car B = 60 miles per hour
Explanation:
Average speed of the car A is
(Equation A) and Average speed of the car B is
(Equation B), where
and
are the distances and
and
are the times at which are travelling the cars A and B respectively.
We have to convert the time to the correct units:
1 hour and 36 minutes = 96 minutes

From the diagram (Please see the attachment), we can see that at the time they meet, we have:
(Equation C)
(Equation D)
From Equation A and C, we have:

208-x+16 = x
208 + 16 = 2x

x = 112 miles
Replacing x in Equation A:


Replacing x in Equation B:



There are two different processes here:
1) we must add heat in order to bring the temperature of the water from

to

(the temperature at which the water evaporates)
2) other heat must be added to make the water evaporates
1) The heat needed for process 1) is

where

is the water mass

is the water specific heat

is the variation of temperature of the water
If we plug the numbers into the equation, we find

2) The heat needed for process 2) is

where

is the water mass

is the latent heat of evaporation of water
If we plug the numbers into the equation, we find

So, the total heat needed for the whole process is
Answer:
Engine A is able to accelerate a car faster.
Explanation: