Answer: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:
I'm pretty sure it's B because I studied this topic and I'm not right I'm sorry.
Answer:
1. Static electricity is caused by the build up of electrical charges on the surface of objects, while current electricity is a phenomenon from the flow of electrons along a conductor. 2. When objects are rubbed, a loss and/or gain of electrons occurs, which results in the phenomenon of static electricity.
Explanation: