You are going on a car trip with your family across the United States. To your brother's
surprise, the AM radio station that your family
is listening to is coming from a city 600 miles
away. Explain to him how this is possible. Be
sure to describe how the ionosphere affects AM
radio transmissions.​

The desk has a weight of 75 lb and a center of gravity at g. determine the initial acceleration of a desk when the man applies enough force f to overcome the static friction at a and b. also, find the vertical reactions on each of the two legs at a and at b. the coefficients of static and kinetic friction at a and b are ms = 0.5 and mk = 0.2, respectively

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.

Contains chemical energy. a. heat b. light c. natural gas