A) What parts of the EM spectrum are being used? Compare them in terms of wavelength, frequency, and energy.

All?

Explanation:

As wavelengths get shorter, energy increases, and frequency increases. As wavelenghts get longer, energy decreases, and frequency decreases. We can see the visible spectrum where the side UV has the shortest and strongest waves, but the IR side has the longest and weakest wavelengths.

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.