Advertisements
Advertisements
Question
A 50 kg girl wearing high heel shoes balances on a single heel. The heel is circular with a diameter 1.0 cm. What is the pressure exerted by the heel on the horizontal floor?
Advertisements
Solution 1
Mass of girl, m = 50 kg
∴Force on the heel, F = mg = 50 x 9.8 = 490 N
Diameter, D = 1.0 cm = `1 xx 10^(-2)m`
`:. "Area A" =(piD^2)/4 = (3.14xx(1xx10^(-2))^2)/4 = 7.85 xx 10^(-5) m^2`
`:. "Pressure", P = F/A = 490/(7.85xx10^(-5)) = 6.24xx10^6 "Pa"`
Solution 2
Mass of the girl, m = 50 kg
Diameter of the heel, d = 1 cm = 0.01 m
Radius of the heel = `r = d/2 = 0.005 m`
Area of the heel = `pir^2`
= π (0.005)2
= 7.85 × 10–5 m2
Force exerted by the heel on the floor:
F = mg
= 50 × 9.8
= 490 N
Pressure exerted by the heel on the floor:
`P = "Force"/"Area"`
`= 490/(7.85xx10^(-5))`
= 6.24 × 106 N m–2
Therefore, the pressure exerted by the heel on the horizontal floor is 6.24 × 106 Nm–2.
APPEARS IN
RELATED QUESTIONS
Toricelli’s barometer used mercury. Pascal duplicated it using French wine of density 984 kg m–3. Determine the height of the wine column for normal atmospheric pressure.
The pressure on a surface increases with an increase in the thrust on the surface.
The unit of thrust is ..........
How is the thrust related to pressure?
Name two factors on which the pressure on a surface depends.
A sharp pin works better than a blunt pin. Explain the reason.
Find the thrust required to exert a pressure of 50000 pascals on an area of 0.05 m2 ?
Calculate the pressure exerted on a surface of 0.5 m2 by a thrust of 100 kgf.
Find the pressure 200m below the surface of the ocean if pressure on the free surface of liquid is one atmosphere. (Density of seawater = 1060 kg/m3)
In a pressure cooker, the food is cooked faster because ______.
A drinking straw works on the existence of ______.
Analogy
Broader straps: ______:: Thin needles: ______.
Assertion: The pressure at the bottom of the sea is lesser than that near the surface.
Reason: The pressure exerted by a liquid depends upon the depth of the liquid and density of the liquid.
Determine the pressure when a force of 200 N acts on the area
- 20 m2
- 8 m2
Give reasons why:
a single nail pricking the body is painful when compared to lying on a bed of nails.
The pressure in mines is ______ than the sea level.
Hot air is ______ dense than ordinary air.
What is the SI unit of pressure?
Assertion (A): A sleeping mattress is so designed that when you lie on it, a large area of your body comes in its contact.
Reason (R): This reduces the pressure on the body and sleeping becomes comfortable.
A vessel filled with water is kept on a weighing pan and the scale adjusted to zero. A block of mass M and density ρ is suspended by a massless spring of spring constant k. This block is submerged inside into the water in the vessel. What is the reading of the scale?
