# Homework Help: Finding change in momentum

1. Jun 6, 2009

### synchronous

1. The problem statement, all variables and given/known data

Pitcher pitches a .30 kg softball has velocity 14 m/s at an angle of 36 degrees below the horizon just before the bat contacts the ball. What is the magnitude of change in momentum if the ball leaves the bat with a velocity of 23 m/s, vertically downward.

2. Relevant equations

v(i) = <14cos324, 14sin324> = <11, -4.3>
v(f) = <23cos270, 23sin270> = <0, -23>
Delta p = mv(f) - mv(i) = m [v(f) - v(i)]

3. The attempt at a solution

Delta p = .30(<0, -23> - <11, -4.3>) = <-3.3, -5.7>

Magnitude of delta p = sqrt[(-3.3)^2 + (-5.7)^2] = 6.6

2. Jun 6, 2009

### LowlyPion

I'm not sure I follow your values for the components of the initial velocity.
I get ...

14 cosine36 = 11.34
14 sine 36 = 8.23

3. Jun 6, 2009

### synchronous

You're right...not sure how my brain froze for that calculation...must have been a typo...thought I double-checked it! Thanks!