Question

(b) peluru yang digunakan dalam acara itu adalah berbentuk sfera dengan jejari 5.5 cm. the shot - put ball used in the event is spherical shape with a radius of 5.5 cm (i) hitung isipadu peluru tersebut dalam cm³. calculate the volume of the shot - put ball in cm³. (ii) peluru itu akan disalut dengan cat anti - karat. hitung luas permukaan peluru yang perlu dicat. the shot - put ball will be coated with anti - corrosion paint. calculate the surface area of the shot - put ball that needs to be painted. (guna / use π = 22/7) 4 markah 4 marks

Explanation:

Step1: Recall volume formula for sphere

The volume formula of a sphere is $V = \frac{4}{3}\pi r^{3}$, where $r = 5.5$ cm and $\pi=\frac{22}{7}$.

Step2: Substitute values into volume formula

$V=\frac{4}{3}\times\frac{22}{7}\times(5.5)^{3}=\frac{4}{3}\times\frac{22}{7}\times5.5\times5.5\times5.5=\frac{4\times22\times5.5\times5.5\times5.5}{3\times7}\approx696.83$ $cm^{3}$

Step3: Recall surface - area formula for sphere

The surface - area formula of a sphere is $A = 4\pi r^{2}$, where $r = 5.5$ cm and $\pi=\frac{22}{7}$.

Step4: Substitute values into surface - area formula

$A = 4\times\frac{22}{7}\times(5.5)^{2}=4\times\frac{22}{7}\times5.5\times5.5=\frac{4\times22\times5.5\times5.5}{7}\approx379.94$ $cm^{2}$

Answer:

(i) The volume of the shot - put ball is approximately $696.83$ $cm^{3}$.
(ii) The surface area of the shot - put ball that needs to be painted is approximately $379.94$ $cm^{2}$.