Two cars travel on a horizontal road towards each other at speeds equal to 10 and 20 m / s, respectively

Two cars travel on a horizontal road towards each other at speeds equal to 10 and 20 m / s, respectively. The mass of each car is 1 t. Determine the kinetic energies of the cars: a) in the frame of reference connected with the Earth; b) in the frame of reference associated with the first car.

a) in the frame of reference associated with the Earth: E1 = (mv ^ 2) / 2 = 1000 * 100/2 = 50kJ
b) in the frame of reference associated with the first car: E1 = 0;
Ek2 = (mv ^ 2) / 2 = (1000 * (10 + 20) / 2 = 450kJ

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.