Question

4. A force of 20 N is exerted on the head of a drawing pin using one's thumb to push the pin into a drawing board. The top (head) of the pin has area 100 mm^2 and the tip of the pin has area 0.1 mm^2. Calculate the pressure on the thumb and on the drawing board. (Ans. 2 bar,2000 bar)​

Answer 1

Answer:

Answer is already given

Explanation:

we know,

• Pressure = F/A,

where F = force,A = area of cross section.

Given,

• F = 20 N,
• A of head = 100 mm² = 0.1 m²
• A of tip = 0.1 mm² = 0.0001 m²

First we will calculate the pressure on thumb :-

P = F/A

p = 20/0.01

p = 2 N/m²

Now, pressure on drawing board :-

P = F/A

P = 20/0.0001

P = 2000 N/m²

Hope it helps

Answer 2

Answer:

Pessure on thumb=200Nm-2

Pressure on drawing board=200000Nm-2

Explanation:

P=F/A

P=20/0.1m2=200Pa

P=20/0.0001=200000Pa