Haven't taken physics but I would assume if her friend is standing in front of her that you would add up the speeds and get 30 km/hr.
In object in motion stays in motion; speed
X - rays are highly penetrating electromagnetic radiations that are formed when the cathode rays strikes a dense metal.
It has many characteristics such as :
- travels with the speed of light.
<span> energy produced by flow of electric charge describes a electrical energy
because movement of electric charge do effect the work on system
so correct option is B
hope it helps</span>
<span>The force of attraction by which terrestrial bodies tend to fall toward the center of the earth strongly. If i'm wrong, correct me. otherwise i hope this helped.</span>
