What kinetic energy does a brick have a mass of 1500 g and flying at a speed of 50 km / h?

We assume that the brick moves in a closed system. For a closed system, the kinetic energy is:
Ek = (mV ^ 2) / 2, where Ek is the kinetic energy of the brick (J), m is the mass of the brick (m = 1500 g = 1.5 kg), V is the speed of the brick (V = 50 km / h = 50 * 1000/3600 m / s = 13.9 m / s).
Let’s calculate the kinetic energy of the brick:
Ek = (1.5 * 13.9 ^ 2) / 2 ≈ 145 J.
Answer: The kinetic energy of a brick is 145 J.