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 m^{2} what is the pressure
between the elephant and the ground?
2. (a) How
many cm^{2} are there in a m^{2}?
(b) convert 25 000 N/m^{2 }to N/cm^{2}.
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 cm^{2}. What is the pressure between her heel
and the ground. Give your answer in both
N/cm^{2} and N/m^{2 }.
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 cm^{2}


2

5000 N

2.5 m^{2}


3


3 m^{2}

400 N/m^{2}

4


12 cm^{2}

25 N/cm^{2}

5

100 N


10 Pa

6


100 cm^{2}

80 Pa
