Question

The volume of a 500 g sealed packet is 350 cm3. Will the packet float or sink in water if the density of
water is 1 g cm-? What will be the mass of water displaced by this packet?
​

Answer 1

Given:

• Mass = 500 g

• Volume of packet = 350 cm³

• Density of water = 1 g cm-³

To be calculated:

Calculate the mass of water displaced by the packet ?

Formula used:

Density = Mass / Volume

Solution:

Density of packet = Mass of packet / volume of packet

★Substituting the values in the above formula,we get

Density of packet = 500 g / 350 cm³

= 100 g / 70 cm³

= 1.42 g.cm‐³

The density of packet is more than density of water.

Hence, Packet will sink in water.

We have now to calculate the mass of water :

Density of water = Mass of water / Volume of water

★ Substituting the values in the above formula

⇒ 1 g . cm‐³ = Mass of water / 350 cm³

⇒ Mass of water = 1 g.cm‐³ × 350 cm³

⇒ Mass of water = 350 g

Thus, the mass of water displaced by packet is 350 grams.

Answer 2

Explanation :

Volume of packet is 350 cm³ . Mass of packet is 500 g. Density of water is 1 g cm-³.

Will the packet sink or float in water? What will be mass of water displaced?

___________________________

Here mass of packet = 500 g

We know that,

Mass of object = Volume × Density

Substituting values,

⇒ 500 = 350 × Density

⇒ Density = 500/350

⇒ Density = 1.43 gcm-³

∵ Density of packet > Density of water

∴ Packet will not float on water. Packet will sink in water.

___________________________

___________________________

Again we have,

□ Density of water = 1 g/cm³

□ Volume of water = 350 cm³

∵ Volume of water = Volume of packet

We will use same formula here,

⇒ Mass = 350 cm³ × 1 gcm-³

Here, cm³ & cm-³ will get cancelled.

⇒ Mass = 350 × 1 g

⇒ Mass = 350 g

∴ Mass of water displaced by packet = 350 grams.