Two friends X and Y were going to a party and wore heels. Heels of girl X were 3 inch high and diameter of heels was 2 cm. Another girl Y wore 4 inch high block heel having sides 4 cm x 3 cm. The mass of girl X and Yare 45 kg and 60 kg respectively. If girl X is standing on one foot and girl Y on both feet, the ratio of pressure exerted by X to Y on ground is
Answers
Given:
Heels of girl X = 3 inches
Diameter of heels = 2 cm
Mass of girl X = 45 kg
Heels of girl Y = 4 inches
Sides = 4 cm x 3 cm
Mass of girl Y= 60 kg
To find:
Ratio of pressure exerted by X and Y on the ground.
Solution:
Pressure by X who is standing only on one foot = Force exerted/ area
= Mass* g / πr²
= 45 * 10 / (22/7)*0.01*0.01
Pressure by Y = Force / Area
= Mass *g / Area
= 60 *10/ 0.04*0.03
Since the girl Y is standing on both feet, her pressure should be halved because the area of her heels is doubled:
Pressure by Y = 2*60 *10/ 0.04*0.03
Ratio of pressure of X and Y = Pressure of X / Pressure of Y
= ((4500000*7)/22) / (6000000/2*12)
= (45*7/22) / (60/24)
=(7*45*24) / (22*60)
= (7*9*2) / 22
= 63 : 11
Therefore the pressure ratio exerted by X and Y is 63:11.