Answer:
We can use 2 g H = v2^2 - v1^2 or
v2^2 = 2 g H + v1^2
Since 88 ft/sec = 60mph we have 30 mph = 44 ft/sec
The object will return with the same speed that it had initially so the object
starts out with a downward speed of 44 ft/sec
Then v2^2 = 2 * 32 ft/sec^2 * 160 ft + 44 (ft/sec)^2
v2^2 = (2 * 32 * 160 + 44^2) ft^2 / sec^2 = 12180 ft^2/sec^2
v2 = 110 ft/sec
The Doppler Effect provides the equation for the
calculation of apparent frequency:
f=fo[vo/(vo-vr)]
where:<span>
vo=source wave velocity
vr=relative speed between source and observer
f=apparent frequency
fo=source frequency </span>
<span>
The velocity of the doppler wave is
v=λf</span>
where λ is light wavelength. Hence,
v=λfo[vo/(vo-vr)]
Based on the equation, we can say that wave
velocity will always be defined by one and only one wavelength.
Therefore the answer is letter C.
<span> </span>
Answer:
2.68 hours
Explanation:
A.) Suppose the wind blows out from the west (with the air moving east). The pilot should then head her plane to northwest direction to move directly north.
B.) Given that plane flies at a speed of 102 km/h in still air. And the wind blows out from the west (with the air moving east) at a speed of 46 km/h.
The plan resultant speed can be calculated by using pythagorean theorem.
Resultant Speed = Sqrt( 102^2 + 46^2 )
Resultant Speed = Sqrt( 12520)
Resultant speed = 111.89 km/h
From the definition of speed,
Speed = distance/time
Where distance = 300 km
Substitute the resultant speed and the distance into the formula.
111.89 = 300/time
Time = 300/111.89
Time = 2.68 hours
Therefore, it take her 2.68 hours to reach a point 300 km directly north of her srarting point
Distance = (30+40+50) = 120 km
It's back where it started, so displacement = zero