Question

The sum of the weights of an iron piece and of a copper piece is 1280gm. The volume of the copper piece is twice that of the iron piece. If the weight of 1 cubic centimetre of iron is 7.8gm and that of copper is 8.9gm. find the volume of each piece.​

Answer 1

Answer:

The density of water is maximum at 4°C.

The

Step-by-step explanation:

Answer 2

Let the weight of the iron piece = x gm. Then,

Weight of the copper piece = (1280 – x) gm

Volume of x gm iron = x/(7.8)cm³ [ volume = mass/ density]

Volume of (1280 – x) gm copper =(1280 - x)/8.9 cm³

$\bold{ \therefore \: \frac{2x}{7.8} = \frac{1280 - x}{8.9} (given)}$

$\small \bold{ \implies \: 2x \times 8.9 = 7.8 \times (1280 - x)}$

$\bold{ \implies \: 17.8x = 9984 - 7.8x}$

$\bold{ \implies \: 17.8 + 7.8x = 9984}$

$\bold{\implies \: 25.6x = 9984}$

$\bold{\implies \: x = \frac{9984}{25.6} = 390}$

Volume of x gm iron =

$\bold{ \frac{390}{7.8} = 50 \: {cm}^{3} }$

Volume of (1280 – x) gm copper =

$\bold{\frac{1280 - 390}{8.9} = 100 \: cm {}^{3}}$