An airline employee throws two suitcases, one 15 kg and one 20 kg in mass, onto a 25 kg luggage trolley. If you know that the trolley is initially at rest and the employee imparts a horizontal speed of 3 m / s to the 15 kg suitcase and a horizontal speed of 2 m / s to the 20 kg suitcase, determine the final speed of the trolley if the first suitcase that is thrown on it is: \n
a) the 15 kg. \n
b) the 20 kg.\n