Some bacteria are propelled by biological motors that spin hair-like flagella. a typical bacterial motor turning at a constant angular velocity has a radius of 1.57 x 10-8 m, and a tangential speed at the rim of 2.21 x 10-5 m/s.
(a) what is the angular speed (the magnitude of the angular velocity) of this bacterial motor?
(b) how long does it take the motor to make one revolution?

(a)

(b)

Explanation:

The angular speed is a measure of the rotation speed. Thus, It is defined as the angle rotated by a unit of time:

The arc length in a circle is given by:

s is the length of an arc of the circle, so .

Replacing (2) in (1):

a) Now, we calculate the angular speed:

b) We use (1) to calculate the time it takes to make one revolution, which means that is .

260 miles per hour

explanation:

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.