A major artery with a cross-sectional area of 1.00cm2 branches into 18 smaller arteries, each with an average cross-sectional area of 0.400cm2. By what factor is the average velocity of the blood reduced when it passes into these branches

The velocity in the smaller arteries will be reduced by a factor of 0.139

Explanation:

The flow rate of blood is going to stay the same when it is transferred from the major artery to the smaller ones.

flow rate = Velocity * Area

Since the flow rate remains constant, we have:

Flow rate in major artery = combined flow rate in smaller arteries

Velocity in Major artery * 1.00 = Velocity in smaller artery * (0.4 * 18)

Thus, the velocity in the smaller arteries will be reduced by a factor of 0.139

the answer to this question is 60 n

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.