Question

High pressure, low pressure

- state whether it is desirable to have high pressure or low pressure

- explain why this is desirable


(Use the words force, area, and pressure in your answers)


1) A hotel has a lounge with a wooden dance floor. A notice says that people must not wear stiletto heels.


2) A butcher regularly sharpens the knives which he uses to cut up meat.


3) A needle used for sewing has a sharp point at one end. The person sewing often wears a thimble on a finger to push the needle through the fabric.

Answer 1

Answer:

applied force

So we have

1. A hotel has a lounge with a wooden dance floor. A notice says that people must not wear stiletto heels.

Here less pressure is required on the floor so the surface area must be large

2. A butcher regularly sharpens the knives which he uses to cut up meat.

Here large pressure is required so the area of contact must be small

3. A needle used for sewing has a sharp point at one end. The person sewing often wears a thimble on a finger to push the needle through the fabric.

Here large pressure is required so the area of contact must be small

2 a)

Since elephant has four foot

so we have total contact area given as

A = 4(0.1) = 0.4 square meter

2 b)

Pressure due to elephant weight is given as

2 c)

When elephant lift its one foot

Now we have

3)

When applied force is given as

F = 6 N

Area of contact is 2 square meter

Now the pressure is given as

Explanation: