Answer:
If sound waves of the same energy were passed through a block of wood and a block of steel, which is more dense than the wood, the molecules of the steel would vibrate at a slower rate. Sound moves faster through denser air because the molecules are closer together in dense air and sound can be more easily passed on.
Explanation:
<span>The force will be zero if the wagons are moving at a constant speed (i.e. not accelerating), as there is no frictional force to overcome. If the wagons are accelerating, the force will be proportional to the acceleration, and 20% of the force applied by A.</span>
I think B......................
Answer: 0.999959 c
Explanation:
According to the special relativity theory, time is measured differently by two observers moving one relative another, according to the Lorentz Transform Equation, as follows:
t = t’ / t=t^'/√(1-(v)2/c2 )
where t= time for the moving observer (relative to the spacecraft, fixed on Earth) = 110 years.
t’= time for the observer at rest respect from spacecraft = 1 year
v= spacecraft constant speed
c= speed of light
Solving for v, with a six decimals precision as a multiple of c, we get:
v = 0.999959 c
