Military personnel also use periscopes in some gun turrets and in armoured vehicles. More complex periscopes using prisms or advanced fibre optics instead of mirrors and providing magnification operate on submarines and in various fields of science
Answer:
F = 50636.873 N
Explanation:
given,
bucket of water = 700-kg
length of cable = 20 m
Speed = 40 m/s
angle of the cable = 38.0°
let air resistance be = F
tension in rope be = T
T cos 38° = m×g..................(1)
..........(2)
equation (1)/(2)


F = 50636.873 N
Hence the force exerted on the bucket is equal to F = 50636.873 N
D.
All follow an elliptical path that has two foci, rather than a circular path.
Kepler found paths are elliptical, not circular
Answer:
Therefore the rate of corrosion 37.4 mpy and 0.952 mm/yr.
Explanation:
The corrosion rate is the rate of material remove.The formula for calculating CPR or corrosion penetration rate is

K= constant depends on the system of units used.
W= weight =485 g
D= density =7.9 g/cm³
A = exposed specimen area =100 in² =6.452 cm²
K=534 to give CPR in mpy
K=87.6 to give CPR in mm/yr
mpy


=37.4mpy
mm/yr


=0.952 mm/yr
Therefore the rate of corrosion 37.4 mpy and 0.952 mm/yr.
Answer:
2 seconds
Explanation:
The frequency of a wave is related to its wavelength and speed by the equation

where
f is the frequency
v is the speed of the wave
is the wavelength
For the wave in this problem,
v = 2 m/s

So the frequency is

The period of a wave is equal to the reciprocal of the frequency, so for this wave:

This means that the wave takes 4 seconds to complete one full cycle.
Therefore, the time taken for the wave to go from a point with displacement +A to a point with displacement -A is half the period, therefore for this wave:
