Nold times, before there were train signals, people who worked on the railroad would often put their ear down to the train track to listen for an oncoming train. why would this result in hearing the train further off than just listening for the train through the air? question 3 options: sound travels slower, but louder through solid material because it is more dense, so the train could be heard better this way. sound travels slower in air because there are often trees and other items blocking the sound. sound waves travel faster in more dense material, and the more dense the material the louder the sound is. people did not do this because sound travels faster through less dense material, like air, rather than more dense materiel, like train tracks.

What’s the percent by mass of carbon in c10h14n2

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.

Plz me ! 1 which of earths spheres contains most of its mass? a atmosphere b hydrosphere c geosphere* d biosphere 2 erosion and weathering are examples of which types of forces? a constructive forces b destructive forces* c gravitational forces d inertia-related forces 3 which of the following statements about earths atmosphere is true? a earths atmosphere contains 78% water vapor which is essentail to life b earths atmosphere contains 21% oxygen c earths atmosphere contains carbon dioxide which all life forms require d earths atmosphere allows radiation from the sun to pass through it and warm earths surface* 4 the strenght of the force of gravity between two objects is determined by which of the following factors? select all that apply a the messes of the objects* b the distance between the objects* c the volumes of the objects d the surface area of the objects 5 earth and moon are kept in there respective orbits due to the influence of a inertia b gravity c gravity and inertia* d neither gravity or inertia if you answer all questions right i will give