Arailroad car of mass 2.50 3 104 kg is moving with a speed of 4.00 m/s. it collides and couples with three other coupled railroad cars, each of the same mass as the single car and moving in the same direction with an initial speed of 2.00 m/s. (a) what is the speed of the four cars after the collision? (b) how much mechanical energy is lost in the collision?

2.5 m/s

37.5KJ

Explanation:

Let be the initial velocity of rail road car ,coupled cars & Final velocity of system respectively.

Conserving momentum

Therefore Final velocity of system is 2.5m/s

(b)Mechanical Energy lost =Initial Kinetic Energy -Final Kinetic Energy

answer

procedural programming, object-oriented programming

explanation

procedural programming is a type of computer programming language that specifies a series of well structured steps and procedures   within its development period of time. it contains a systematic order of statements, functions and commands to complete a computational task or program. it is centered on creating procedures. while object oriented programming is a programming language that is centered on creating objects rather that actions and data rather than logic.. it has four principles which are inheritance, polymorphism, abstraction and encapsulation

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it