Answer:
electricity is the answer
Abs and piper have a great time and
Answer:
Speed of faster train equals 29 mph
Explanation:
Let the speed of slower train be 'x' miles per hour and the speed of faster train be 'y' miles per hour.
Distance that slower train covers in 2 hours=
Distance that faster train covers in 2 hours=
Since they move at right angles the distance between them can be found by Pythagoras formula as

It is given that 
Using this in the above equation we get

This is a quadratic equation in 'x'
Comparing with standard quadratic equation
we get value of x as

Thus speed of faster train = 28.58 mph
Speed of faster train = 19 mph
<span>A compound machine is a combination of two or more "Machines"
Hope this helps!</span><span />
Answer:
That the Sun was the center of the universe.
Explanation:
Ptolemy believed in geocentrism, which means that the Earth is the center of the Universe. This was also supported by Aristotle. Copernicus on the other hand believed in a heliocentric system, which proposes that the sun is the center of the universe.