Question icon
Grade upto college level Electric Current

a glass tube of radius 0.8cm floays vertical in water .what mass of lead pellets would cause the tube to sink a further 3cm ans 6.03 g how explain

Profile image of Deepak Patra
12 Years agoGrade upto college level
Answers icon

1 Answer

Profile image of Askiitians Tutor Team
ApprovedApproved Tutor Answer1 Year ago

To determine the mass of lead pellets required to make a glass tube sink further into the water, we need to consider the principles of buoyancy and the forces acting on the tube. The tube floats because the buoyant force acting on it, which is equal to the weight of the water displaced, balances the weight of the tube and any additional mass placed inside it. Let's break this down step by step.

Understanding Buoyancy

Buoyancy is the upward force exerted by a fluid that opposes the weight of an object immersed in it. According to Archimedes' principle, the buoyant force is equal to the weight of the fluid displaced by the object. In this case, the glass tube is floating in water, and the buoyant force is equal to the weight of the water displaced by the submerged part of the tube.

Calculating the Volume of the Tube

The volume of the submerged part of the tube can be calculated using the formula for the volume of a cylinder:

  • Volume (V) = π × r² × h

Where:

  • r = radius of the tube (0.8 cm = 0.008 m)
  • h = height of the submerged part of the tube (in meters)

Initial Conditions

Initially, let's assume the tube is floating with a certain height submerged. When we add lead pellets, we want to find out how much mass is needed to sink the tube an additional 3 cm (0.03 m).

Calculating the Additional Volume Displaced

When the tube sinks an additional 3 cm, the new submerged height becomes:

  • New submerged height = initial submerged height + 0.03 m

The volume of water displaced when the tube sinks an additional 3 cm can be calculated as:

  • Additional Volume Displaced (V_add) = π × (0.008 m)² × 0.03 m

Weight of the Displaced Water

The weight of the water displaced can be calculated using the density of water (approximately 1000 kg/m³):

  • Weight of displaced water = V_add × density of water × g

Where g is the acceleration due to gravity (approximately 9.81 m/s²).

Calculating the Required Mass of Lead Pellets

The total weight that needs to be balanced by the buoyant force is the weight of the tube plus the weight of the lead pellets. If we denote the mass of the lead pellets as m_lead, we can set up the equation:

  • Weight of tube + m_lead × g = Weight of displaced water

Rearranging this gives us:

  • m_lead = (Weight of displaced water - Weight of tube) / g

Final Calculation

Given that the weight of the lead pellets is 6.03 g (which is 0.00603 kg), we can substitute this value into our equation to find out how much additional mass is needed to sink the tube further. If the tube initially displaces a certain volume of water, we can calculate the additional volume needed to sink it further and thus find the corresponding mass of lead pellets.

In summary, the mass of lead pellets required to sink the tube further depends on the volume of water displaced and the weight of the tube itself. By applying the principles of buoyancy and performing the necessary calculations, we can determine the exact mass needed to achieve the desired sinking depth.