I only know about the Water tank which is the most accurate. You place your body in it, and weights are added I think. Somehow some measurements are gathered to get your body fat weight. Online calculators exist, as well as electronic waves that are sent int your body, the echo is recorded and analyzed.
Answer:
9 cm
-36 cm
Explanation:
u = Object distance
v = Image distance
f = Focal length = 12
m = Magnification = 4

Lens equation

Object distance is 9 cm

Image distance is -36 cm (other side of object)
Answer:
4.123 * 10∧4 kg
Explanation:
mass of car M' = 3.34 * 10∧4 kg
energy loss E = 19/100 K
from law of conservation of momentum ,
M' V' = ( M' + M'' ) v
V = M' V' / ( M' + M'' )
Initial kinetic energy is K' = (M' V')² / 2
final kinetic energy K" = 81 K' /100
= (M' V')² 81 / (200) = ( M' + M'' ) v²/ 2
therefore , M' / ( M' + M" ) = 0.81
mass of caboose is , M" = 1.234 M' - M'
M" = .234 M'
= 0,234 ( 3.34 * 10∧4 kg)
= 4.123 * 10∧4 kg
Answer:
Faraday invented the electromagnetic rotation.
Explanation:
Faraday invented a device called electromagnetic rotation, Faraday got a rotation with magnetic force, he used a cable, mercury, and a magnet.
The cable would rotate around the magnet, this would be a beginning for the electromagnetic technology.
For example:
The Homopolar motor or called electric motor was created for Faraday's invention.
We can find electric motor in Washing machines, fans, turbines, even in motorcycles and electric cars.
Interference if the hardest to remove due to the superposition of the frequencies of the radio waves