A body weighing 2 kg moves at a speed of 10 m / s. What is the mass of a body with the same kinetic

A body weighing 2 kg moves at a speed of 10 m / s. What is the mass of a body with the same kinetic energy at a movement speed of 5 m / s /

kinetic energy E = mV ^ 2/2
since the kinetic energies are equal in both situations, we compose the equation
E1 = E2
m1V1 ^ 2/2 = m2V2 ^ 2/2
(2kg * 100 m ^ 2 / s ^ 2) / 2 = (m2 * 25 m ^ 2 / s ^ 2) / 2
100 J = (m2 * 25 m ^ 2 / s ^ 2) / 2
2 * 100 J = m2 * 25 m ^ 2 / s ^ 2
200 J / 25 m ^ 2 / s ^ 2 = m2
m2 = 8 kg
Answer: body weight in the second case – 8kg