What is the speed of a falling book dropped from 4.50m?

[Dino18]

A Physics book, mass unknown, is dropped 4.50m. What speed does the book have just before it hits the ground?

 

[cupid.callin]

here v(final) = asked
h = 4.5
a=?
v(initial)= ?

can you tell 2 "?"

 

[Dino18]

initial velocity is 0 and a=?

 

[cupid.callin]

what is a in free fall?

 

[Dino18]

Oh.. 9.8 m/s

 

[cupid.callin]

there you go

now you know which eqn to use?

 

[Dino18]

vf^2=vi^2+2ad

 

[cupid.callin]

very good!

 

[Dino18]

Thx a lot