What is the common velocity of the arrow

[missmerisha]

Homework Statement

An arrow of mass 100 g is fired with an initial horizontal velocity of 40 m s–1 to the right at an apple of mass 80 g that is initially at rest on a horizontal surface. When the arrow strikes the apple, the two objects stick together. What is the common velocity of the arrow and apple after the impact?

Homework Equations

Momentum = mass * velocity

The Attempt at a Solution

Initial Momentum of the Arrow
p=m*v
=(.1)(40)
= 4

4=.08* v
therefore v= 50 m/s

the answer says it's 22m/s

 

[rl.bhat]

4=.08* v
therefore v= 50 m/s
This is wrong.
When the arrow strikes the apple, the two objects stick together.
So rewrite the above equation.

 

[missmerisha]

I don't get it
If the momentum is 0 then the velocity is 0

 

[rl.bhat]

Momentum after impact = ( 0.1 + 0.08)*v

 

[Quang]

m1v1 = (m1 + m2)v