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zimovet [89]
3 years ago
7

When starting a heavy train, why will train engineers sometimes back up, stop, and then proceed forward? (This technique is call

ed "bunching slack.")
Physics
2 answers:
fiasKO [112]3 years ago
6 0
It is kind of in the name. it brings the cars closer together then continues to go forward.
Goryan [66]3 years ago
4 0
Maybe....
<span>when going in reverse it makes a tiny gap between each boxcar, then when going forward it pushes or pulls each car one at a time to build momentum rather than moving them all at once...not sure

</span>
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A tall cylinder contains 30 cm of water. oil is carefully poured into the cylinder, where it floats on top of the water, until t
Art [367]

The total gauge pressure at the bottom of the cylinder would simply be the sum of the pressure exerted by water and pressure exerted by the oil.

The formula for calculating pressure in a column is:

P = ρ g h

Where,

P = gauge pressure

ρ = density of the liquid

g = gravitational acceleration

h = height of liquid

Adding the two pressures will give the total:

P total = (ρ g h)_water + (ρ g h)_oil

P total = (1000 kg / m^3) (9.8 m / s^2) (0.30 m) + (900 kg / m^3) (9.8 m / s^2) (0.4 - 0.30 m)

P total = 2940 Pa + 882 Pa

P total = 3,822 Pa

 

Answer:

 The total gauge pressure at the bottom is 3,822 Pa.

6 0
3 years ago
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Which of the following objects would absorb the most light?
RSB [31]

A an opanque object is compared to a black T shirt

7 0
3 years ago
What is the average acceleration of a jet ski that goes from rest to 10 m/s west in 4 s? Take the direction west to be positive,
skad [1K]

|acceleration| = (change in speed) / (time for the change)

                       = (10 m/s - 0)          /  (4 s)

                       =        (10 / 4) (m/s²)

                       =            2.5 m/s² .

The direction of the acceleration is west.
3 0
3 years ago
Josh is designing a lab to separate a mixture of sulfur powder and iron filings. He looks at all the ways to separate a mixture
Stolb23 [73]

Answer:

D) magnetic attraction

Explanation:

Mixture consists of sulfur powder and iron filings . The former is non magnetic and the later is magnetic material . The best way to separate them is to use a magnet . This method is called magnetic separation method . A magnet will attract the iron filling but the sulfur will remain un-attracted . Thus, the two will get separated from each other.

6 0
3 years ago
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Which best describes why Keplers observation of planetary motion is a law instead of a theory
svet-max [94.6K]

Kepler's first law - sometimes referred to as the law of ellipses - explains that planets are orbiting the sun in a path described as an ellipse. An ellipse can easily be constructed using a pencil, two tacks, a string, a sheet of paper and a piece of cardboard. Tack the sheet of paper to the cardboard using the two tacks. Then tie the string into a loop and wrap the loop around the two tacks. Take your pencil and pull the string until the pencil and two tacks make a triangle (see diagram at the right). Then begin to trace out a path with the pencil, keeping the string wrapped tightly around the tacks. The resulting shape will be an ellipse. An ellipse is a special curve in which the sum of the distances from every point on the curve to two other points is a constant. The two other points (represented here by the tack locations) are known as the foci of the ellipse. The closer together that these points are, the more closely that the ellipse resembles the shape of a circle. In fact, a circle is the special case of an ellipse in which the two foci are at the same location. Kepler's first law is rather simple - all planets orbit the sun in a path that resembles an ellipse, with the sun being located at one of the foci of that ellipse.


5 0
3 years ago
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