I would say B. A stable home and varied activities
Basically, the temperature is a result of the average kinetic energy of all the atoms comprising the solid/liquid/gas. In solid, these atoms can just vibrate in place, leaving them to only be able to conduct and radiate heat. However, as you probably know liquids and solids take the shape of their container because the bonds between atoms are loose enough to allow them to freely move around. Due to each individual atom having its own energy, and these atoms being free to move about the liquid/gas they collide with other atoms in the substance. These collisions result in a transfer of energy. Finally, lower energy atoms "sink" and higher energy atoms "rise" thus creating a "convection current".
Acceleration = ( final velocity - intial velocity ) / time
= (60-0)m/s / 3s
= 20 m/s2
the answer is a
Force applied by the machine to over come resistance
Answer: 4nmeter
Explanation: The two observer a and b will measure the same wavelength since the speed of the space craft is very small compared with the speed of light c. That is
V which is the speed of space craft 15000km/s = 15000000m/s
Comparing this with the speed of light c 3*EXP(8)m/s we have
15000000/300000000
= 0.05=0.1
Therefore the speed of the space craft V in terms of the speed of light c is 0.1c special relativity does not apply to object moving at such speed. So the wavelength would not be contracted it will remain same for both observers.