The change in kinetic energy was 34 kJ.
Step 1. Calculate the total mass
Total mass = 100 kg + 200 kg = 300 kg
Step 2. Calculate the initial kinetic energy (KE_i)
v = 0
KE_i = ½ mv^2 = ½ × 300 kg × 0^2 = 0
Step 3. Calculate the final kinetic energy (KE_f)
KE_f = ½ mv^2 = ½ × 300 kg × [15 m·s^(-1)]^2 = 34 000 kg·m^2s^(-2) = 34 000 J = 34 kJ
Step 4. Calculate the change in kinetic energy
ΔKE = KE_f - KE_i = 34 kJ – 0 = 34 kJ
