Answer: 80 feet
Step-by-step explanation:
We can write these as fractions and do cross multiplication with the numerator being the height of the object while the denominator being the length of the shadow:
5 * 128 = 8x
640 = 8x
80 = x
Thus, the height of the lighthouse is 80 feet tall.
12-9=3
3+12+4,5=19,5
19 hours and 30 min
Use the Pythagorean therm , you know the a^2+b^2=c^2
Answer:
The equation that represents the motion of the string is given by:
.....[1] where t represents the time in second.
Given that: A = 0.6 cm (distance above its resting position) , k = 1.8(damping constant) and frequency(f) = 105 cycles per second.
Substitute the given values in [1] we get;
or
(a)
The trigonometric function that models the motion of the string is given by:

(b)
Determine the amount of time t that it takes the string to be damped so that 
Using graphing calculator for the equation
let x = t (time in sec)
Graph as shown below in the attachment:
we get:
the amount of time t that it takes the string to be damped so that
is, 0.5 sec