Answer:
Step-by-step explanation:
this is confusing b/c they are asking about two trains traveling at differnt speeds, but.. if you put the speeds together and make one train... imaginary.. ofc... traveling at the speed of both trains combined... when will it be 50 miles from the station?
maybe you can solve that? I'll solve it below.. but.. if you can.. try it now, on your own
below is my answer... don't look until you have solved yours :P
80+70= 150kph
when will this have traveled 50Km?
you may be able to see that it will take 1/3 of an hour to travel 50 km
so 60 minutes times 1/3 = 20 minutes :)
Answer:
a) -13.9 ft/s
b) 13.9 ft/s
Step-by-step explanation:
a) The rate of his distance from the second base when he is halfway to first base can be found by differentiating the following Pythagorean theorem equation respect t:
(1)

(2)
Since:

When x = 45 (the batter is halfway to first base), D is:

Now, by introducing D = 100.62, x = 45 and dx/dt = 31 into equation (2) we have:

Hence, the rate of his distance from second base decreasing when he is halfway to first base is -13.9 ft/s.
b) The rate of his distance from third base increasing at the same moment is given by differentiating the folowing Pythagorean theorem equation respect t:

(3)
We have that D is:

By entering x = 45, dx/dt = 31 and D = 100.63 into equation (3) we have:

Therefore, the rate of the batter when he is from third base increasing at the same moment is 13.9 ft/s.
I hope it helps you!
Kim's age is twice of that of her sister. We'll let k2 = Kim and k = Kim's sister.
So, k2. When you add Kim's age to her sister age you get 36.
Because Kim is twice the age of her sister k2. And because it said 'add' then we put a + sign. k2 + s = 36. Now let's solve it.
k2 + k = 36 < Given
3k = 36 < Combine like terms
k = 12 < Divide both sides by 3
We know Kim's sister is 12 y/o but what about Kim herself? Earlier we assigned Kim to k2. Substitute 12 for k and you get 12(2) = 24
Kim's sister is 12 y/o and Kim is 24 y/o
Please give Brainliest!