Question

Write the important formulas in work and energy chapter ​

Answer 1

Explanation:

Work of a constant force

(Force is parallel to displacement)

(Work of force of friction)

W  F x cos

W  F x

W F x   FRIC 

Kinetic energy 2

2

1

E m v K 

Gravitational potential energy

(Near a planet surface) EP  m g h

Gravitational potential energy

r

M m

EP  G

Elastic potential energy 2

2

1

E k x P  

Mechanical (total) energy EM  EK  EP

Mechanical energy conservation EM  0 (all forces are conservative)

EM  WNCF (there are non-conservative forces)

Inelastic collision

p p m v m v m m v BEFORE AFTER

    

( )   1 1  2 2  1  2

Elastic collision

1 1 2 2 1 1 2 2

p p m v m v m v' m v' BEFORE AFTER

     

    

EK Before  EK After

Power

m m u m P F v

t

W P ; 





Unit conversions 1 cal = 4.184 J

1 J = 0.239 cal

1 HP = 736 W (nevertheless there are many definitions)

1 kW·h = 3.6 · 106

J

Answer 2

Answer:

$1) \: \: Work = force \times displacement$

$2) \: \: Work = F \: s \: \cosθ$

$3) When \: θ = {0}^{o} ....\: \: W = F \: s$

$4) When \:θ = {90}^{o} ....\: \: W = 0$

$5) \: \: When \: θ = {180}^{ o} ....W = - F \: s$