The ratio of the distance moved by the point at which the effort is applied in a simple machine to the distance moved by the point at which the load is applied, in the same time. In the case of an ideal (frictionless and weightless) machine, velocity ratio = mechanical advantage. Velocity ratio is sometimes called distance ratio.
Explanation:
Mass of the wheel, m = 49 kg
Radius of the hoop, r = 0.73 m
Initial angular speed of the wheel, 
Final angular speed of the wheel, 
Time, t = 22 s
(a) If I is the moment of inertia of the hoop. It is equal to,
We know that the work done is equal to change in kinetic energy.
W = -1858.05 Joules
(b) Let P is the average power. It is given by :
P =84.45 watts
Hence, this is the required solution.
The statemengt is <em>false</em>. Electromgnetic waves do not require a medium to transfer energy. They can transfer energy through vacuum (empty space with nothing in it). If electrimagnetic waves needed a medium to move through from place to place, then we could never see the sun, and also it would get very cold here.
Similarities:
The halogens like noble gases are gaseous im nature. Example,
Chlorine, bromine are halogens and argon , xenon are noble gases.
Both are non-metals.
Differences: Halogens are very reactive because their octet needs only one electron tk complete. But, the nobles gases are quite stable and unreactive because the have complete octets.
