Question

Car 1 has 7 times the mass of car 2, but only 0.6 as much kinetic energy. What is the ratio between the speeds of the two cars (v1/v2)? You must type your answer as a numerical value.

Answer 1

Answer:0.29

Explanation:

Given

Car 1 has 7 times the mass of car 2

but 0.6 times the kinetic energy of car 2

suppose car 2 has the mass m and $v_2$ be the velocity

then car 1 has a mass of 7 m

Kinetic Energy of car 1

$K_1=0.5\times 7m\times v_1^2-------1$

Kinetic energy of car 2

$K_2=0.5\times m\times v_2^2------2$

divide 1 and 2 we get

$\frac{K_1}{K_2}=\frac{7v_1^2}{v_2^2}$

$\frac{v_1}{v_2}=\sqrt{\frac{0.6}{7}}$

$\frac{v_1}{v_2}=0.29$