Question

A cube of balsa wood (side length = 0.25 m) is tied with a string to the bottom of a waterfilled container. The wood is completely immersed. What is the tension in the string?

Answer 1

Answer:

The tension in the string is 128.625 N.

Explanation:

Given that,

Side length = 0.25 m

Density of balsa wood = 160 kg/m³

We need to calculate the volume of the cube

$V= l^3$

$V=(0.25)^3$

$V=0.015625\ m^3$

We need to calculate the mass

Using formula of density

$\rho=\dfrac{m}{V}$

$m=\rho\times V$

Put the value in to the formula

$m=160 \times0.015625$

$m=2.5\ kg$

We need to calculate the weight

$W = mg$

$W=2.5\times9.8$

$W=24.5\ N$

We need to calculate the buoyant force

$F=V\rho g$

Where, V = volume

$\rho$ = gravity

g = acceleration due to gravity

Put the value into the formula

$F =0.015625\times1000\times9.8$

$F=153.125\ N$

We need to calculate the tension in the string

$T=F-mg$

$T=153.125-24.5$

$T=128.625\ N$

Hence, The tension in the string is 128.625 N.