Help with acceleration, magnitude, and direction of force

[jayyafeelme]

Homework Statement

As a baseball is being caught, its speed goes from 28.0 m/s to 0.0 m/s in about 0.0050 s. The mass of the baseball is 0.140 kg.

What is the baseball's acceleration?
What are the magnitude and direction of the force acting on it?
What are the magnitude and direction of the force acting on the player who caught it?

Homework Equations

f=ma?

The Attempt at a Solution

28.0 m/s x 0.140 kg = 3.92

 

[LowlyPion]

Homework Statement

As a baseball is being caught, its speed goes from 28.0 m/s to 0.0 m/s in about 0.0050 s. The mass of the baseball is 0.140 kg.

What is the baseball's acceleration?
What are the magnitude and direction of the force acting on it?
What are the magnitude and direction of the force acting on the player who caught it?

Homework Equations

f=ma?

The Attempt at a Solution

28.0 m/s x 0.140 kg = 3.92

You calculated momentum. The force will be change in momentum over the time period.

If v = a*t you should be able to figure the acceleration.

 

[jayyafeelme]

so 28.0 m/s x 0.0050 s?

 

[LowlyPion]

so 28.0 m/s x 0.0050 s?

Not the way I do algebra.

 

[jayyafeelme]

v divided by 0.0050 s? please help me i really need to get this done

 

[LowlyPion]

v divided by 0.0050 s? please help me i really need to get this done

That gives you acceleration.

 

[jayyafeelme]

but isn't v = velocity? and v = distance/time? they don't give me a distance

 

[jayyafeelme]

someone help please

 

[borgwal]

Can you do better than randomly multiplying quantities? Pion gave you v=a*t, which quantities do you know in this equation?

 

[jenglish]

you're going to need an equation that can find the acceleration (or deceleration) when given an initial as well as final velocity and time.

I suggest

Vf=Vo+at

that should give you acceleration