Calculate the kinetic energy of a 100.0-kg meteor approaching the Earth at a speed of 10.0 km/s. Remember that 1 km = 1000 m.

Kinetic Energy = (1/2) (mass) (speed squared)Mass = 100 kgSpeed = 10 km/s = 10,000 m/sSpeed squared = 100,000,000 m²/s²1/2 (M)(V²) = 1/2 (100) (100,000,000) = 5,000,000,000 joules  (5 x 10⁹ J)That's  5 billion joules.That's the amount of energy a 100-watt light bulb uses in  579 days.

KE=1/2 x mass x speed^2Substitute:KE=1/2 x 100 x 10000^25000000000J of KESo either 5 gigajoulesOr 5x10^9J