1. CHAPTER 3:
FORCES &
PRESSURE

3. Defined as force acting normally per unit area
of the surface.
Unit : 1 Pa = 1 Nm-2
Factor affect the pressure ;
Force
area of the surface
mass

4. Factors affect the pressure

5. Example question;
1.The diagram given shows
the block of cuboid 0.5m x 0.7m
x 0.9m. Its weight is 15 N.
Calculate :
a) A maximum pressure
b) A minimum pressure

8. Applications :
1. knife, sole with studs, thumbtacks, etc.
2. Tyre of tractor, snowshoes, feet of elephant,

16. Exercise ;

17. exercise
1. A pressure of 1000 Pa is acting on a floor of area
012. m2. what is the resultant force produce?
2. A women wears a pair of shoes where the total
surface area in contact is 60 cm2. if the pressure on
the floor due to this woman is 75000 Nm -2, what is
the weight of the woman?
3. A wooden cuboid has a dimension 0.4m ×0.01 m ×
0.2 m and has a mass of 640 g. determine the
smallest pressure produced by the cuboid when it is
placed on a flat surface?