A college student wants to toss a textbook?

Question

Can you help me out with this physics 040 question? It's really hard to start out!
A college student wants to toss a textbook to his roommate who is leaning out of the window directly above him. He throws the book up with a velocity of 8.0 m/s. The roommate catches the book while it is travelling 3.0 m/s[upward].
a) How long was the book in the air?
b) How far did the book travel in the upward direction?
I'm understanding that acceleration due to gravity = 9.80m/s^2. Please help!

Answer 1

Both of the previous answers are correct. Basically you will use the following kinematics equations for any type of problem like this:

xf = x0 + v0 t + 1/2 a t^2
vf = v0 + 1/2 a t
vf^2 = v0^2 + 2 a x

Answer 2

a) v=u-gt v=3,u=8
3=8- 9.8t
t=5/9.8 seconds

b) v^2=u^2+-2gs

s=(u^2-v^2)/2g

Answer 3

v_i= 8.0 m/s
v_f= 3.0 m/s
g=9.80 m/s^2
a= -9.80 m/s^2 (if g is positive going down, must be neg. up)
t=?
d=?

v_f= v_i + at
3.0 = 8.0 + (-9.80) t
t = 0.51 s

v_f^2 = v_i^2 + 2ad
(3.0)^2= (8.0)^2 + 2 (-9.80) d
d= 2.8 m