Answer: The person sitting in the middle of the train sees the back of the train enter ing the tunnel before the front end comes out.
Explanation:
Answer:
0.02 m/s^2
Explanation:
change in velocity= 4.5m/s - 2.3m/s = 2.2 m/s
acceleration= change in velocity/change in time
acceleration= 2.2/120= 0.0183
= 0.02 (to 2 significant figures)
Well, there you have a very important principle wrapped up in that question.
There's actually no such thing as a real, actual amount of potential energy.
There's only potential <em><u>relative to some place</u></em>. It's the work you have to do
to lift the object from that reference place to wherever it is now. It's also
the kinetic energy the object would have if it fell down to the reference place
from where it is now.
Here's the formula for potential energy: PE = (mass) x (gravity) x (<em><u>height</u></em><u>)</u> .
So naturally, when you use that formula, you need to decide "height above what ?"
If you're reading a book while you're flying in a passenger jet, the book's PE is
(M x G x 0 meters) relative to your lap, (M x G x 1 meter) relative to the floor of the
plane, (M x G x 10,000 meters) relative to the ground, and maybe (M x G x 25,000 meters)
relative to the bottom of the ocean.
Let's say that gravity is 9.8 m/s² .
Then a 4kg block sitting on the floor has (39.2 x 0 meters) PE relative to the floor
it's sitting on, also (39.2 x 3 meters) relative to the floor that's one floor downstairs,
also (39.2 x 30 meters) relative to 10 floors downstairs, and if it's on the top floor of
the Amoco/Aon Center in Chicago, maybe (39.2 x 345 meters) relative to the floor
in the coffee shop that's off the lobby on the ground floor.
Answer:
0.001067 Wb
Explanation:
Parameters given:
Magnetic field, B = 0.77 T
Angle, θ = 30º
Width = 0.4cm = 0.04m
Length = 0.4cm = 0.04m
Magnetic flux, Φ(B) is given as:
Φ(B) = B * A * cosθ
Where A is Area
Area = length * width = 0.04 * 0.04 = 0.0016 m²
Φ(B) = 0.77 * 0.0016 * cos30
Φ(B) = 0.00167 Wb
Answer:
Explanation:
1) Make sure the service portion of the structure stays above the highest probable water level.
2) Make sure the support structure in contact with the water can withstand the tidal flows
3) Consider whether the added restriction of the proposed structure will altar the height of, or water velocity contained in, the tidal exchanges.
4) Consider whether a dock needs to have mechanisms to compensate for large sea level changes.
