1. An EM wave representing 650 nm laser light is traveling in the +zˆ direction. At one point in space and time, the electric fi
1 answer:
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Answer:
103.5 meters
Explanation:
Given that a stunt person has to jump from a bridge and land on a boat in the water 22.5 m below. The boat is cruising at a constant velocity of 48.3 m/s towards the bridge. The stunt person will jump up at 6.45 m/s as they leave the bridge.
The time the person will jump to a certain spot under the bridge can be calculated by using the formula below:
h = Ut + 1/2gt^2
since the person will fall under gravity, g = 9.8 m/s^2
Also, let assume that the person jump from rest, then, U = 0
Substitute h, U and g into the formula above
22.5 = 1/2 * 9.8 * t^2
22.5 = 4.9t^2
22.5 = 4.9t^2
t^2 = 22.5/4.9
t^2 = 4.59
t =
t = 2.143 seconds
From definition of speed,
speed = distance /time
Given that the boat is cruising at a constant velocity of 48.3 m/s towards the bridge, substitute the speed and the time to get the distance.
48.3 = distance / 2.143
distance = 48.3 * 2.143
distance = 103.5 m
Therefore, the boat should be 103.5m away from the bridge at the moment the stunt person jumps?
Answer:
n = 1810
A = 25 mm
Explanation:
Given:
Lateral force amplitude, F = 25 N
Frequency, f = 1 Hz
mass of the bridge, m = 2000 kg/m
Span, L = 144 m
Amplitude of the oscillation, A = 75 mm = 0.075 m
time, t = 6T
now,
Amplitude as a function of time is given as:
or amplitude for unforce oscillation
or
or
Now, provided in the question Amplitude of the driven oscillation
the value of the maximum amplitude is obtained
thus,
Now, for n people on the bridge
Fmax = nF
thus,
max amplitude
or
n = 1810
hence, there were 1810 people on the bridge
b)
since the effect of damping in the millenium bridge is 3 times
thus,
b=3b
therefore,
or
or
or
A = 0.025 m = 25 mm