8. Which of the following travel in the same type of wave? Choose all that apply
a. A cry for help.
b. An X-ray in the hospital.
c. The red light from a stop signai.
d. A ray of sunlight through space.

Determine the amount of work done when a crane lifts a 100-n block form 2m above the ground to 6m above the ground

What is the role of the water cycle in maintaining freshwater levels in lake and rivers?

Aheavy boy and a lightweight girl are balanced on a massless seesaw. the boy moves backward, increasing his distance from the pivot point. what happens to the seesaw? it is impossible to predict without knowing additional information. the side the boy is sitting on will tilt downward. the side the girl is sitting on will tilt downward. nothing; the seesaw will remain balanced.