Explanation:
Gravity
Gravity is one major force that creates tides. In 1687, Sir Isaac Newton explained that ocean tides result from the gravitational attraction of the sun and moon on the oceans of the earth (Sumich, J.L., 1996).
Answer: 4 ft/s
Explanation:
Given
height of man
speed of person 
height if street light
Let x be the distance between person and street light and y be the length of his shadow
From diagram
as the two triangle ADE and ABC are similar therefore we can say that




differentiate above Equation w.r.t time we get


Answer:
The tension in string is found to be 188.06 N
Explanation:
For the vibrating string the fundamental frequency is given as:
f1 = v/2L
where,
f1 = fundamental frequency = 335 Hz
v = speed of wave
L = length of string = 28.5 cm = 0.285 m
Therefore,
v = f1 2L
v = (335 Hz)(2)(0.285)
v = 190.95 m/s
Now, for the tension:
v = √T/μ
v² = T/μ
T = v² μ
where,
T = Tension
v = speed = 190.95 m/s
μ = linear mass density of string = mass/L = 0.00147 kg/0.285 m = 5.15 x 10^-3 kg/m
Therefore,
T = (190.95 m/s)²(5.15 x 10^-3 kg/m)
<u>T = 188.06 N</u>