What directly controls breathing, heartbeat, and muscle movement in the human body?

A. electrical signals

B. chemical reactions

C. variations in temperature

D. the heart

Vector A has magnitude 2 units and is directed to the north. Vector B has magnitude 5 units and is directed to the south. Calculate the magnitude and direction of A+B

A current of 12 amps is measured in a circuit with a total resistance of 9.0 ohms. What is the size of the voltage source that supplies this circuit?

Frustration Occurs When

Three polarizing filters are stacked with the polarizing axes of the second and third at 45.0∘ and 90.0∘, respectively, with that of the first.

What will the wire's resistance be if it is stretched to twice its original length without changing the volume of the wire?

Water is a compound. O A. True B. False

How do air quality scientists ensure the air is cleaned? What steps do they take?

Is a mirrors surface opaque or transparent or translucent?

Sound waves can combine to become bigger or smaller true or false

Archimedes supposedly was asked to determine whether a crown made for the king consisted of pure gold (density of gold is 19.3 * 103 kg/m3). According to legend, he solved this problem by weighing the crown first in air and then in water.