Why are radio waves considered harmless while ultraviolet waves and x-rats considered harmful

A space craft is moving towards mars. it's rocket engines are turned off. as the spacecraft nears mars, what will hapen to the pull of the planet's gravity?

If the Velocity of a moving object is doubled what happens to its kinetic energy

A shot-putter exerts an unbalanced force of 140 N on a shot giving it an acceleration of 19 m/s2. What is the mass of the shot?

The assessment technique used by health care providers that utilizes a stethoscope to listen to lung sounds is called A. palpation. B. percussion. C. observation. D. auscultation.

Which phenomenon causes an object to appear bent from above the surface of one medium to below the surface of another medium?

A penny falls from a windowsill which is 25.0 m above the sidewalk. How much time does a passerby on the sidewalk below have to move out of the way before the penny hits the ground?

Show that the Newton has the units of mass times acceleration.

Light travels at 150000000km from the sun to earth in 8 minutes. What speed is this in Km/s

Electricity problem (coulomb's law)

An observer (O) spots a plane (P) taking off from a local airport and flying at a 29° angle horizontal to her line of sight and located directly above a tower (T). The observer also notices a bird (B) circling directly above her.