[SEC 3] CHAPTER 6 - pressure

Question 1

define pressure

Answer 1

pressure is the force acting normally or perpendicularly per unit area

Question 2

what is the formula for pressure?

Answer 2

pressure = force/area

Question 3

what is the SI unit for pressure

Answer 3

Pascal (Pa)
1Pa = 1Nm^-2

Question 4

what is the formula to find pressure of a liquid?

Answer 4

Pressure = pgh
(p is rho)

Question 5

what is the atmospheris pressure at sea level?

Answer 5

1.01 x 10^5 Pa

Question 6

what is the formula to find pressure of an object in a liquid?

Answer 6

Pobject = Pliquid + Patm
Pobject = hpg + Patm

Question 7

what is the unit of measurement in a barometer?

Answer 7

(cm Hg) or (mm Hg)

Question 8

why do we get crushed by Patm?

Answer 8

air inside your body exerts an internal pressure that is equal in magnitude

Question 9

explain what happens when someone drinks from a straw

Answer 9

1. person sucks air from straw
2. lesser air particles inside straw to exert force on inner walls of straw
3. external pressure > internal pressure
4. Atm pressure pushes down on the liquid, which goes up the straw to persons mouth

Question 10

why is mercury used in barometers instead of water?

Answer 10

because its high density allows for a much shorter and more practical column to measure atmospheric pressure accurately