Answer:
m g sin theta = force of object along incline due to gravity
N μ = frictional of incline on object where N is the normal force
N = m g cos theta force perpendicular to incline
m g sin theta = N μ = μ m g cos theta
μ = tan theta = tan 38 = .78
The energy transferred by a sound wave is independent of its speed. However, the type of medium affects this due to the differences in the distances between particles in different media, i.e. sound travels faster through solids than gases as the solid particles are much closer together, so they collide more frequently allowing the sound to travel faster. Additionally, temperature affects the distances between particles in a medium, increasing them with increasing heat, causing slower sound travel. Therefore the answer is the third option.
Hope this helps!
It's kind of funny really. The guy who invented the idea in the first place had actually been made fun of because the thought of that happening was improbable in their mind. Also, Wegener ( the guy who invented the idea) was not even a geologist but a meteorologist. But later it had been backed up due to earthquakes being record consecutively in one area, and the graphs turning out differently.
Answer:

Explanation:
When the rock is immersed in unknown liquid the forces that act on it are shown as under
1) Tension T by the string
2) Weight W of the rock
3) Force of buoyancy due to displaced liquid B
For equilibrium we have 
=
When the rock is suspended in air for equilibrium we have

When the rock is suspended in water for equilibrium we have
+
=
Using the given values of tension and solving α,β,γ simultaneously for
we get

Solving for density of liquid we get


The earth is so round that we can run around it in five million days