energy and Impulse Example 3 R E = 6.371 10 6 m G = 6.67384 10 -11 - - PowerPoint PPT Presentation

▶

Nov 03, 2023 211 likes •279 views

Class 27: Examples on conservation of energy and Impulse Example 3 R E = 6.371 10 6 m G = 6.67384 10 -11 m 3 kg -1 s -2 Escape velocity = ? Power Power is the rate of work done by a force: dW P dt But dW F

SLIDE 1

Class 27: Examples on conservation of energy and Impulse

SLIDE 2

Example 3 RE = 6.371106 m G = 6.67384 × 10-11 m3 kg-1 s-2 Escape velocity = ?

SLIDE 3

Power Power is the rate of work done by a force: Unit for power: Watt (W)  Js-1

v F P dt r d F P dt dW P r d F dW dt dW P                 

But

Same as the one we use in electrical appliances

SLIDE 4

Normal force Like friction, normal force is NOT a conservative force. For example: 4kg 2kg 3m/s 4m/s

lost) is (energy 34J 34J 16 18 ) 4 )( 2 ( 2 1 ) 3 )( 4 ( 2 1

2 2

    

Total mechanical energy before collision = Total mechanical energy after collision

Mechanical energy is not conserved in a collision.

SLIDE 5

p I v m v d m dt dt v d m dt F I v m p Momentum dt p d F dt v d m F Law s Newton' dt F I Impulse                             

   

Impulse and Momentun F

SLIDE 6

An important case In a collision, normal force F  and t  0 #1 #2

I12 I21

p p p p I I

1 2 1 2 1 2 2 1

           

 