Question

Question
(a) A boy weighs 50 N. The area of contact of his two feet is 10 cm². What pressure does he exert on the ground if he stands on one foot?

(b) A man weighs 250 N. Suppose he stands on a pointed edge with base area 5 cm² How much pressure does he exert on the ground?

(c) Now compare (i) and (ii) to find out the following.

(i) Who exerts more force on the ground, the boy in (i) or the man in (ii)?

(ii) Who exerts greater pressure on the ground, the boy or the man?

(iii) Who is likely to sink into the ground, the man standing on a pointed edge or the boy standing on one foot and why?​

Answer 1

Explanation:

given :

• (a) boy weight = 50 N

• area of contact of his two feet is = 10 cm

• b) man weight = 250 n

• base area = 5 cm

• c) compare (i) and (ii) to find out the following.

• 2. Who exerts more force on the ground, the boy in (i) or the man in (ii)?

• 3. likely to sink into the ground

• boy standing on one foot and why?

to find :

• (a) he stands on one foot = ?

• b) How much pressure does he exert on the ground = ?

• c) find out the following. = ?

solution :

ans 1.

• two feet area = 10 cm

• one foot contact of area = 5cm

then,

• we will divide 5 ÷ 10000 m = 0.0005 m

• p = force/area 50 ÷ 0.0005

• = 100000 pressure

answer 2 .

man weight = 250 N

base and area = =5cm²-5x10 -4 m²

pressure = force/ area

= 250 ÷ 5 x 10 -4

= 50×10 = 5× 10 pa

ans 3

a) ans

• weight of boy = 50 N

• weight of man = 250 N

NR = MG

• weight for boy NR = 50 N

• weight for man NR = 250 N

• NR is exert on ground

weight of man exert more force on ground

b)ans

• pressure of boy = 50 N

• pressure of man = 250/ 5 = 50

weight of man exert more pressure on ground

c) answer

• edge meaning small so man is likely to sink

Answer 2

Hey Atlas ! Sorry for late !

A copied spam answer was blocking me from answering!

Here is your Solution !

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Given :

• Surface area of Legs of Boy = 10cm²
• Base area on which the man is standing = 5cm²
• Weight of Boy =50N
• Weight if Man = 250 N

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To Find :

1. Pressure exerted by Boy on ground
2. Pressure exerted by man on ground
3. Compare the following:

• Who has greater pressure , The boy in 1) or the man in 2)
• Who is exerting more Pressure on ground
• Who is more likely to sink in ground, the boy or the man ?

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Formula To be applied:

We will use the formula of pressure exerted.

Pressure Exerted = Force/Area

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Process :

We will first find the Pressure of the boy on ground in one leg.

Weight is the Force which is calculated by mass and gravity.

Then, we will calculate the pressure of the man on the ground.

Then we will compare the both pressures as asked in question

• the person with higher pressure is most likely to sink in ground

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Solution :

1] We will first find out the surface area of contact of boy and ground :

surface Area of both = 10 cm²

area of contact = 0.001 m²

so, Surface contact area of 1 leg = 0.001m²/2 = 0.0005 m²

Hence, pressure = 50N/0.0005

or, Pressure exerted = 1,00,000 Pa

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2] we will now fund the pressure exerted by the man on the ground

Surface area of contact = 5cm²

Or, Surface Area of contact = 0.0005 m²

Weight = 250 N

$\tt{pressure = \frac{weight}{area} }$

$\implies \tt{pressure = \frac{250}{0.0005} }$

$\tt{ \implies pressure = 500000 \: pa}$

Pressure = 500000 Pa

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3] i) As we can clearly see that the Weight of man in case 2] is 250 N

And, the the Weight of Boy in case 2] is 50 N

The Nothing but the Force exerted on any object by us in accordance to gravity .

Hence, the Weight exerted by man in case2] is greater

ii] As we have already seen in the above question, Weight exerted by man is greater :

So, pressure exerted by man = 500000 pa

Pressure exerted by Boy = 100000 Pa

Hence, pressure exerted by man is greater .

iii] As we saw in the above question, the pressure exerted by the man is greater,

Hence, the ground will be pressed very much by him , so The Man is likely to sink in the ground .

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Hope this Answer help you My friend!