Technically, this delivers a lot of energy into the Earth, but it’s
spread out over a large enough area that it doesn’t do much more than
leave footprints in a lot of gardens. A slight pulse of pressure spreads
through the North American continental crust and dissipates with little
effect. The sound of all those feet hitting the ground creates a loud,
drawn-out roar which lasts many seconds.
Sound intensity = 1/(r^2)
That is Sound intensity is indirectly proportional to the distance. Therefore, sound becomes 9 times less intense.
a 10 kg block reaches a point with a velocity of 15 m per second and slides down a rough track my the coefficient of the kinetic energy between the two surface ab and the block iis0.52
Question 18: a
question 19: b
question 20: c
Answer:
it can kill you cell and win you kill you no cell no life
Explanation:
