9514 1404 393
Answer:
5 seconds
Step-by-step explanation:
Suppose the front parts of the trains meet at point A. Since both are the same length and traveling the same speed, each will pass point A in time ...
time = distance/speed
time = (1/18 mi)/(40 mi/h) = (1/720 h) × (3600 s)/(1 h) = 5 s
That is, the rear part of each train will be at point A 5 seconds after the front part.
The rear parts will pass each other 5 seconds after the front parts meet.
Answer:
34.0 m
Step-by-step explanation:
The total angle sum in a triangle should be 180° hence the missing angle will be given by
180°-145°-28°=7°
Using sine rule
By substituting 160 for m, 145° for M and 7° for L then
Making l the subject then
Professor Dan Healy, one of my Engineering instructors back in prehistoric times, had a favorite way of showing us how to do this kind of problem ... I mean the kind that's incredibly easy, but your own fear gets in the way and convinces you that you can't handle it. Here is Prof. Healy's method.
For a few moments, call the square root of 5 by the name "cow".
cow - x = 4 . Solve this equation for 'x' :
Add 'x' to each side of the equation: cow = 4 + x
Subtract 4 from each side: cow - 4 = x
Now, we can put the real value back in place of 'cow' : <u>√5 - 4 = x</u>
That right there is a perfect solution. But If you absolutely need to
know the number, then grab your calculator:
√5 = 2.2361 (rounded)
x = √5 - 4 = 2.2361 - 4 = <u>-1.7639</u> (rounded)
Answer: 1.18
Step-by-step explanation:
Z = (x - mean) / standard deviation
Z = (85 - 71.4) / 11.5
Z = 13.6 / 11.5 = 1.18
