1. A nurse is using a syringe to inject a medication into a patient's vein.

The syringe has a cross-sectional area of 0.5 cm^2 and the needle has a

cross-sectional area of 0.05 cm^2. If the nurse applies a force of 10 N on

the plunger, what is the pressure exerted by the fluid on the needle tip?

A) 1000 Pa

B) 2000 Pa

C) 10,000 Pa

D) 20,000 Pa

Answer: D) 20,000 Pa

Rationale: The pressure in a fluid is given by P = F/A, where F is the force

and A is the cross-sectional area. The pressure is the same throughout the

fluid, so we can equate the pressure at the plunger and the pressure at the

needle tip. Therefore, F/A = F'/A', where F' is the force at the needle tip

and A' is the cross-sectional area of the needle. Solving for F', we get F' =

F(A'/A) = 10 N (0.05 cm^2 / 0.5 cm^2) = 1 N. Then, using P = F'/A', we

get P = 1 N / 0.05 cm^2 = 20,000 Pa.

2. A nurse is measuring the blood pressure of a patient using a

sphygmomanometer. The cuff is wrapped around the upper arm and

inflated until the blood flow in the brachial artery is stopped. The nurse

then slowly releases the air from the cuff and listens for the sounds of

Korotkoff using a stethoscope. The first sound indicates the systolic

pressure and the last sound indicates the diastolic pressure. If the nurse

hears the first sound when the cuff pressure is 120 mmHg and the last

sound when the cuff pressure is 80 mmHg, what is the patient's blood

pressure?

A) 120/80 mmHg

B) 80/120 mmHg

C) 120 + 80 mmHg

D) 120 - 80 mmHg

Answer: A) 120/80 mmHg

Rationale: Blood pressure is expressed as a ratio of systolic pressure over

diastolic pressure, where systolic pressure is the maximum pressure in the

arteries during a heartbeat and diastolic pressure is the minimum pressure

in the arteries between heartbeats. The cuff pressure represents the

external pressure applied to the artery by the cuff. When the cuff pressure

is equal to or higher than the systolic pressure, no blood can flow through