What do contour lines on a topographic map show? location of game trails lakes and rivers roads and highways elevation of the ground?

Which type of current is produced by a wire breaking magnetic field lines and changing the polarity? a. alternating b. direct c. straight d. alternating and direct

Debbie places two shopping carts in a cart corral she pushes the first cart which then pushes a second cart what force is being exerted

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s.part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.