how long would it take to stop a 0.145kg baseball traveling 45m/s using a force of 550N?

Question

anonymous · Answer

f = m*a
550 = 0.145*a
a = ?

anonymous · Answer

Kinematic equataion:
v = v + at
0 = 45 + a*t
solve for t, a is found from f=ma eqaution
make sense?

anonymous · Answer

Answer=.01186 
YES OR NO

theeric · Answer

Looks good to me.

anonymous · Answer

but if u apply back into the equation to check. It says it's not right

theeric · Answer

Hmm...
$F_\text{net}=ma\implies a=\dfrac{F_\text{net}}{m}$

Then, definition of acceleration,
$a=\dfrac{v_f-v_i}{\Delta t}\implies\dfrac{v_f-v_i}{a}=\Delta t$

And our variables are:
$t=?$
$a=?$
$v_f=0$
$v_i=45\ [\text m/\text s^2]$
$F = 550\ [\text N]$
$m=.245\ [\text{kg}]$

anonymous · Answer

mass is not .245

theeric · Answer

$m=.145\ [\text{kg}]$, sorry! That's what I typed in. So, what do you get for $a$?

theeric · Answer

How are you checking it with an equation?

anonymous · Answer

@adamarbour
"Answer=.01186 "
"YES OR NO"
yes, time to stop baseball = 0.01186 seconds.

when you 'plugged it back in' did you plug it into the right equation? in the end, this is how the 2 equations should look.
550 = 0.145*3793                  [True]
0 = 45 +(-3793 )*0.01186      [True]