<span>If a plane has a velocity of 300 km/h and a tailwind of 20 km/h, then the vectors of both forces would add (assuming that the tailwind is blowing exactly at the airplanes back) to a total of 320 km/h. Hope it helps
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Light<span> refracts whenever it </span>travels<span> at an angle into a substance with a </span>different<span>refractive index (optical density). This change of direction is </span>caused<span> by a change in speed. For example, when </span>light travels<span> from air into water, it slows down, causing it to continue to travel at a </span>different<span> angle or direction.</span>
Answer:
Explanation:
we know that
as we see that 
relative error
Where X_1 IS HEIGHT OF ROCK
IS THE HEIGHT OF ROAD
= uncertainity in measuring distance
Putting all value to get uncertainity in angle
solving for 
we get
First I’ll show you this standard derivation using conservation of energy:
Pi=Kf,
mgh = 1/2 m v^2,
V = sqrt(2gh)
P is initial potential energy, K is final kinetic, m is mass of object, h is height from stopping point, v is final velocity.
In this case the height difference for the hill is 2-0.5=1.5 m. Thus the ball is moving at sqrt(2(10)(1.5))=
5.477 m/s.
