Question

Two objects whose masses are in ratio 2:3 are moving with speed in the ratio 4:5.calculate ratio of their kinetic energies.

Answer 1

2:3 =M:m => M=2m/3 4:5=V:v=>V=4v/5 KE= 1/2*M*V^2 = 16mv^2/75 ke=1/2*m*v^2 KE:ke = 16mv^2/75/1/2mv^2 = 32:75 If it helps rate 5 stars

Answer 2

Explanation:

It is given that,

Let m₁ and m₂ are masses of two objects and v₁ and v₂ are their speeds. The energy possessed by an object due to its motion is called the kinetic energy.

$\dfrac{m_1}{m_2}=\dfrac{2}{3}$

and $\dfrac{v_1}{v_2}=\dfrac{4}{5}$

Let E₁ and E₂ are kinetic energies of two objects such that,

$E_1=\dfrac{1}{2}m_1v_1^2$............(1)

$E_2=\dfrac{1}{2}m_2v_2^2$............(2)

Taking ratios of equation (1) and (2) as :

$\dfrac{E_1}{E_2}=\dfrac{m_1}{m_2}\times (\dfrac{v_1}{v_2})^2$

$\dfrac{E_1}{E_2}=\dfrac{2}{3}\times (\dfrac{4}{5})^2$

$\dfrac{E_1}{E_2}=0.426$

So, the ratio of their kinetic energies is 0.426:1. Hence, this is the required solution.