Question

In the arrangement shown, a car of certain mass 'm' is in equilibrium by applying a force of 25 N. If the density of liquid taken is $0.9c{m}^{-3}$, then find the mass of the car.

Answer 1

Let m be the mass of the car
$\frac{m}{400\times {10}^{-4}}=\frac{25}{5\times {10}^{-4}}+8\times 0.9\times {10}^3\times 9.8$
$\frac{m}{400\times {10}^{-4}}=\frac{25\times {10}^{-1}}{5\times {10}^{-4}}$

$M=492kg$