Question

if you are holding a 2- kg book in the palm of your hand and if the area of contact between your hand and the book is 0.003m² then find out the pressure that is exerted on your hand by the book​

Answer 1

Answer:

mass of book = 2kg

area in contact = 0.003m²

pressure:-

mass of object/area in contact

= 2kg/0.003m²

= 666.67 kg/m²

= 667kg/m² or 667pa

Answer 2

Given :

• Mass of the book = 2 kg

• Area of contact between hand and the book is 0.003 m².

To find :

• The pressure exerted on the hand by the book

Solution :

The acceleration of the book when it is hold in hand is in downward direction i.e , acceleration due to gravity. So the acceleration on the book is acceleration due to gravity.

The relation between Force , mass and acceleration is given by ,

$\boxed{\bf{F = ma}}$

Since here a = g ,

$: \implies \boxed{\bf{F= mg}}$

We have ,

• m = 2 kg
• g = 9.8 m/s²

$: \implies \bf \: F = (2 \: kg)(9.8 \: m {s}^{ - 2} ) \\ \\ : \implies \bf \: F = 19.6 \: kg.m {s}^{ - 2} \\ \\ : \implies \bf \: F = 19.6 \: N$

Now , The relation between Pressure , Force and area of contact is given by ,

$\dag\:{\boxed{\bf{P = \frac{F}{A} }}}$

We have ,

• F = 19.6 N
• A = 0.003 m²

Substituting the values ,

$: \implies \bf \: P = \dfrac{19.6 \: N}{0.003 \: m {}^{2} } \\ \\ : \implies \bf \: P = 6533.3 \: N {m}^{ - 2} \\ \\ : \implies \bf \: P = 6533.3 \: pa$

Hence , The Pressure exerted by the book on the hand is 6,533.3 pa (or) 6,533.3 N/m²