# Soccer - What was the impulse on the soccer ball

#### gansta344u

1. Homework Statement
A 0.40 kg soccer ball approaches a player
horizontally with a velocity of 18 m/s to the
north. The player strikes the ball and causes
it to move in the opposite direction with a
velocity of 24 m/s.
What impulse was delivered to the ball by
the player? Answer in units of kg · m/s.

2. Homework Equations
M(v)f-M(v)i=impulse

3. The Attempt at a Solution

Related Introductory Physics Homework Help News on Phys.org

#### LowlyPion

Homework Helper
Re: Momentum

1. Homework Statement
A 0.40 kg soccer ball approaches a player
horizontally with a velocity of 18 m/s to the
north. The player strikes the ball and causes
it to move in the opposite direction with a
velocity of 24 m/s.
What impulse was delivered to the ball by
the player? Answer in units of kg · m/s.

2. Homework Equations
M(v)f-M(v)i=impulse

3. The Attempt at a Solution

The key here is direction.

If it comes in at 18m/s and reverses then it returns at -24m/s.

-24 - 18 = -42

#### The Bob

Re: Momentum

The key to this is directions. Choose one and then all velocities are either positive or negative relative to that. Does that help?

The Bob

P.S. It's not my night; second after post, apologies once again.

Last edited:

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving