Physics

# Key Equations

PhysicsKey Equations

### 9.1Work, Power, and the Work–Energy Theorem

 equation for work $W=fd W=fd$ force $f=w=mg f=w=mg$ work equivalencies $W=P E e =fmg W=P E e =fmg$ kinetic energy $KE= 1 2 m v 2 KE= 1 2 m v 2$ work–energy theorem power $P= W t P= W t$

### 9.2Mechanical Energy and Conservation of Energy

 conservation of energy $K E 1 +P E 1 =K E 2 +P E 2 K E 1 +P E 1 =K E 2 +P E 2$

### 9.3Simple Machines

 ideal mechanical advantage (general) $IMA= F r F e = d e d r IMA= F r F e = d e d r$ ideal mechanical advantage (lever) $IMA= L e L r IMA= L e L r$ ideal mechanical advantage (wheel and axle) $IMA= R r IMA= R r$ ideal mechanical advantage (inclined plane) $IMA= L h IMA= L h$ ideal mechanical advantage (wedge) $IMA= L t IMA= L t$ ideal mechanical advantage (pulley) ideal mechanical advantage (screw) $IMA= 2πL P IMA= 2πL P$ input work $W i = F i d i W i = F i d i$ output work $W o = F o d o W o = F o d o$ efficiency output