Final Question and Math

How long does it take for an EXPO marker to hit ground from waist height? And what shutter speed would be needed? 

Finding the Formula 

Potential Energy (PE) = Kinetic Energy (KE) 

PE=mgh 

KE=1/2m*v^2

In this case 

*m=mass

*g=acceleration due to gravity (constant of 9.8 m/s^2)

*h=height 

*v=velocity (velocity=height/time)

Simplified! 

PE=KE

mgh=1/2m*v^2

2(mgh)=v^2

Square root of (2(mgh))=v

V=d/t BUT we want to find time, so t=d/v

Final Formula: T=d/(square root(2(mgh)))

d=floor to waist height 

d or h = 0.99 m

m = 13.3 g

g = 9.8

Time = .99/(square root(2(13.3*9.8*.99)=0.0616

Into a fraction: 0.0616=77/1250

Closest shutter speed! 1/15