Monday, 8 September 2014

PRESSURE


PRESSURE  

1. An elephant stands on one leg. The elephant has a weight of 48 000 N. If the area of the base of one of its feet is 0.03 m2 what is the pressure between the elephant and the ground?

2. (a) How many cm2 are there in a m2?
    (b) convert 25 000 N/m2 to N/cm2.

3. A girl wearing a stiletto heeled shoes stands on one heel. Her weight is 580 N and the area of one heel is 0.5 cm2. What is the pressure between her heel and the ground. Give your answer in both  N/cm2 and N/m2 .

4. Why does lying on a ladder help you to reach someone trapped in thin ice?

5. Why do some roofs have warning signs about using a ladder to walk across them?

6. How does lying flat out stop you sinking into quicksand?

7. Explain why does it helps to keep tools like saws and chisels sharp?

8. Copy and complete the following table:


Force (N)
Area of contact
Pressure
1
200 N
20 cm2

2
5000 N
2.5 m2

3

3 m2
400 N/m2
4

12 cm2
25 N/cm2
5
100 N

10 Pa
6

100 cm2
80 Pa