Question

A rectangular metal bar has length of 20cm, width of 5cm. Mass of the block is 2kg and its density is 5000kg/m3. Find the height of the metal bar.

Answer 1

Answer: 0.04m

Explanation:

Mass of the block (m) = 2kg

density (p) = 5000kg/m3

Volume (v) = ?

Recall that density is obtained by dividing mass by volume. i.e density = mass / volume

p = m / v

Make v the subject formula

v = m / p

So, v = 2kg / 5000kg/m3

v = 0.0004 m3

Now given that the volume of the rectangular metal bar is 0.0004m3, find its height:

length of metal bar (l) = 20cm

convert length in centimeters to meters

(If 100cm = 1m

20cm = 20/100 = 0.2m)

width of bar (w) = 5cm

convert width in centimeters to meters

(If 100cm = 1m

5cm = 5/100 = 0.05m)

height (h) = ?

Volume of metal bar = l x w x h

0.0004 m3 = 0.2m x 0.05m x h

0.0004 m3 = 0.2m x 0.05m x h

0.0004 m3 = 0.01m² x h

h = 0.0004 m3 / 0.01m²

h = 0.04m

Thus, the height of the rectangular metal bar is 0.04 meters