HELP ASAP! Will make BRAINLEST Which two options are reasons that electromagnetic waves can be used effectively in communication devices?

A. The speed at which they carry information can be varied.
B. They require no wires to carry information
C. Any type of electromagnetic wave can be used for communication.
D. They can travel through either air or other types of matter.

3. a worker pushes a 30.5 kg polished stone along a polished table with a force on bonin a straight line for 5.20 s after starting from rest. there is no friction between thestone and the table. at the end of the table. the stone is hooked to a cable with a lengthof 62.0 cm to rotate it to a rough table to store until they can be picked up. the roughtable has a coefficient of static friction 0.702 with the polished stone. remember that 8= 9.80 m/s2a) what is the speed of the stone when it is hooked to the cable? b) what is the tension in the cable while the stone is rotating? (there is still nofriction)c) how much force is needed to make the stone begin sliding from rest on therough table? ius = 0.70262.0 cm30.5 kg20.5 kg6= 0

What does every magnet possess? a. iron metal b.strong magnetic field c.repulsion d.north and south poles

Which class of lever is a baseball bat? what are the parts of a baseball bat's lever class? describe each one.enter your answer in the space provided.(this question you write your own answer.)i couldn't find the right category, so sorry if this doesn't match.