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## Class 9 Physics (India)

### Course: Class 9 Physics (India)>Unit 4

Lesson 4: Law of conservation of energy

# Law of energy conservation

Let's explore the law of conservation of energy. Created by Mahesh Shenoy.

## Want to join the conversation?

• What's up with all those insensitive comments here? I can understand just well what he explains, and I think his accent/pronunciation is very clear.
• At , if he threw it at an arc, wouldn't there be other factors besides gravity that affect the rate of fall of the object, making U1+K1=U2+K2, not equal to each other, i.e. speed, angle change, air resistance, humidity, dew point, windspeed, arc toss, climate, terminal velocity, etc. These factors can change the amount of energy required to get the object from height A to height B.
• Work's net force would include all of these forces, and he proved conservation of energy for work's net force. Hope this helps!
• 이해가 안되네요.. 무슨말인지 이해가 안가네요 한글 자막을 사용하고 있는데 아직도 이해가 안되네요...
(1 vote)
• I Want To Know If The v In 1/2mv^2 Is Inital Or Final Velocity. The Formula Is Of Work And Energy Theorem Class 9 Physics India?
(1 vote)
• "v" can be the initial or final velocity, but is referred to as velocity in general.
• But , he told the cat was non-living(toy). So, How can it eat a fruit. Lemme make my question clear. How did the toy get energy?
• The toy is possessed
• so when the cat touches the ground, the kinetic energy would be zero again and the potential energy would be full right?
(1 vote)
• as the cat is no longer moving the kinetic energy is 0 - correct.
But as the cat is on the ground the potential energy is also 0.
If the cat is sat in a tree it would have potential energy (it has the potential to fall)
the closer to the ground it gets, the less potential energy.
(1 vote)
• Why is there no transcript for this? I don't mean to be rude, but I can't quite understand what he's saying...
(1 vote)
• At , he says, "right before the cat hits the ground." Wouldn't the cat still have a small amount of potential energy? Thanks.
(1 vote)