0 A Perspex container has a 6 cm square base and contains water to a height of 7 cm (Figure 1.13).

a What is the volume of the water?

b A stone is lowered into the water so as to be

completely covered and the water rises to a height of

9 cm. What is the volume of the stone?

a) 42cm³

b) 12cm³

Explanation:

a) volume=width×height×depth

3cm×2cm×7cm=42cm³

b)3cm×2cm×9cm=54cm³

volume of the stone=54cm³- 42cm³

=12cm³

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

the components of a vector are the parts of the vectors that are to each other.

b perpendicular