Episode 13 explains why the law of conservation of energy is better stated as “the total mechanical energy of a system is conserved unless net external work is applied to the system.” Beginning with an explanation of mechanical energy (1:51) before skating into two practice problems (3:08). Energy is conserved unless there is net external work (7:07). Don’t forget that work can be negative too if it takes energy away from a system. (9:03) The episode concludes with an introduction to power (10:19).The Question of the Day asks: (11:16)A frictionless lab cart is released from rest on a ramp from vertical height “h” and a ball is dropped from rest at the same vertical height. Which is moving faster the moment before impacting the ground?a) the cartb) the ballc) they are moving with the same speedThank you for listening to The APsolute RecAP: Physics 1 Edition!(AP is a registered trademark of the College Board and is not affiliated with The APsolute RecAP. Copyright 2020 - The APsolute RecAP, LLC. All rights reserved.)Website:www.theapsoluterecap.comEMAIL:TheAPsoluteRecAP@gmail.comFollow Us:INSTAGRAMTWITTERFACEBOOKYOUTUBE