A car with a mass of 1800 kg slows from 42 km/h [E] to 28 km/h [E].

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A car with a mass of 1800 kg decelerates from 42 km/h to 28 km/h, and the impulse from the brakes needs to be calculated. The initial attempt yielded an impulse of 2.5 x 10^4 N*s, but the correct answer is 7.0 x 10^3 N*s. The key to solving this problem is converting the velocities from kilometers per hour to meters per second. This conversion is crucial for accurate calculations in physics problems involving momentum and impulse. Proper unit conversion is essential to avoid errors in such calculations.
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Homework Statement


A car with a mass of 1800 kg slows from 42 km/h [E] to 28 km/h [E]. The impulse from the brakes is?

I know its a simple question but I was hoping if I could get a walkthrough. I keep getting the answer 2.5 x 10^4 N*s [W] and the answer is 7.0 x 10^3 N*s


Homework Equations


p=pf-pi


The Attempt at a Solution


(1800)(28[E])-(1800)(42[E])=50400[E]-75600[E]
=25200[W]
=2.5 x 10^4 N*s [W]
 
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Hello CabalGroupie,

Welcome to Physics Forums! :smile:

CabalGroupie said:

Homework Statement


A car with a mass of 1800 kg slows from 42 km/h [E] to 28 km/h [E]. The impulse from the brakes is?

I know its a simple question but I was hoping if I could get a walkthrough. I keep getting the answer 2.5 x 10^4 N*s [W] and the answer is 7.0 x 10^3 N*s


Homework Equations


p=pf-pi


The Attempt at a Solution


(1800)(28[E])-(1800)(42[E])=50400[E]-75600[E]
=25200[W]
=2.5 x 10^4 N*s [W]

Don't forget to convert your velocities from kilometers per hour to meters per second. :wink:
 
Gahh thank you! I feel so incredibly stupid right now that question bothered me way more then it should have
 

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