Why are elements considered the simplest substances on earth

Acertain radio station broadcasts radio waves that have a wavelength of 298cm what is its broadcast frequency?

During the apollo moon missions, astronauts were concerned about the effects of newton's third law of motion when: o a. they ejected waste water, because they were concerned that it would push them off course. o b. they reentered earth's atmosphere, because they were carrying heavy moon rocks. o c. they took off from earth, because a large force was required to generate large acceleration. o d. they detected incoming space debris, because the inertia of the debris could damage their ship.

What is the quantity which is measured by the area occupied below the velocity- time graph?