Answer:
Option as B is correct At the same speed as before
Explanation:
As we know the relation between speed of the wave and tension in string
The speed of wave in stretched string
ν = 
speed of wave is the directly proportional to the square root of tension as mentioned in question tension of string is unaffected when in linear mass density is constant, so we can say that the speed of wave will be the same
Option as B is correct At the same speed as before
Answer:
The pulling force that the man should apply to create an upward acceleration of 
is 
Explanation:
Hi
As it shows in the drawing at the end, we have that the total mass of the man plus the platform is 
, then the force downward 
is 
.
Due the man needs to do a pulling force upward capable of lifting himself and the platform with an acceleration of , this force should create an acceleration greater than gravity by . then 
. Therefore the force should be 
.
Finally, as we have a pulley arrangement connected to the platform, it gives the man a mechanical advantage, so he has to do only half of that upward force
, therefore 
.
A because it depends if the athlete is doing an intense workout he/she would need a sports drink to hydrate them selves
The angle of the Sun above the horizon, which is the solar altitude, influences the intensity ofsolar radiation received at Earth’s surface. At the place on Earth where the Sun is directlyoverhead, the local solar altitude has its maximum value of 90 degrees and solar rays are mostconcentrated. Whenever the Sun is positioned lower in the sky, solar radiation spreads over alarger area of Earth’s horizontal surface and thus is less intense. Solar radiation reaches theplanet essentially as parallel beams of uniform intensity. The nearly spherical Earth presents acurved surface to incoming solar radiation so that the noon solar altitude always varies withlatitude. The intensity of solar radiation actually striking Earth’s atmosphere is greatest at thelatitude where the noon Sun is in the zenith and decreases with distance north and south of thatlatitude. Decreasing solar altitude lengthens the path of the Sun’s rays through the atmosphere.As the path lengthens, the greater interaction of solar radiation with clouds, gases and aerosols<span>reduces its intensity</span>
That measure is known as "acceleration"
a = ΔV / t
Hope this helps!
