Given data
*The particle A has kinetic energy is U_a = 300 J
*Particle B has a mass is m_b = 2 × m_a
*Particle B has a speed is v_b = 1/2 × v_a
The formula for the kinetic energy of the particle B is given as
Substitute the known values in the above expression as
Hence, the kinetic energy of the particle B is U_b = 150 J