The kinetic energy (K.E.) of a body can be calculated using the formula:
K.E. = (1/2) * mass * velocity^2
Given: Mass (m) = 12 kg Velocity (v) = 400 m/s
Using the formula, we can substitute the given values:
K.E. = (1/2) * 12 kg * (400 m/s)^2
K.E. = 0.5 * 12 kg * (160,000 m^2/s^2)
K.E. = 96,000 joules
Therefore, the kinetic energy of a body with a mass of 12 kg and a velocity of 400 m/s is 96,000 joules.