Answer:
D) a Battery
Explanation:
The best real-life example of direct current is a battery. Batteries have positive and negative terminals on a battery, the electrons in the wires will begin to flow to produce a current.
Relatively hot objects emit visible light.
Some examples:
==> the wire coils in the toaster;
==> the spoon that you stuck in the flame on the stove;
==> the fine wire in the lightbulb when current goes through it.
VERY radioactive objects also do that. But if you're actually
standing there watching an object that's THAT radioactive,
then you're in big trouble.
All forces must add up to zero. See pictures below.
The cardiovascular system moves blood through hour body. It is made up of the Heart pumping the blood that is circulated around the body through its networks of arteries, veins and capillaries. The cardiovascular and lymphatic systems together make up the circulatory system.
Line spectra are obtained when individual elements are heated using a high-voltage electrical discharge. This heating causes excitation of the element and a subsequent emission of distinct lines of colored light are obtained. Each element has its own unique emission line spectrum; therefore, if any of the tested substances were the same, their spectra would match. However, this is not the case so none of the substances are the same.
hope it helps!