Newton's laws question -- a car coasts to a stop on a level road

AI Thread Summary
A 1490 kg car traveling at 22.2 m/s coasts to a stop on a level road, experiencing a friction force of 288 N. The initial confusion arose from miscalculating the force and acceleration; the correct acceleration is found by dividing the friction force by the mass, resulting in approximately 0.193 m/s². This deceleration can then be used to calculate the time it takes for the car to stop. The discussion emphasizes the importance of correctly applying Newton's laws to solve for distance traveled during coasting. Understanding these principles is crucial for accurately determining the car's stopping distance.
rmalski
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Homework Statement


A 1490 kg car is is traveling at a speed of 22.2 m/s when the driver let's the car coast on a level road. The friction on the car slowing it down is 288 N. How far will the car coast?

Homework Equations

f=ma

The Attempt at a Solution


i can find the force but i cannot find the distance, i found that the force is 32790N but i am stuck after that
 
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rmalski said:

Homework Statement


A 1490 kg car is is traveling at a speed of 22.2 m/s when the driver let's the car coast on a level road. The friction on the car slowing it down is 288 N. How far will the car coast?

Homework Equations

f=ma

The Attempt at a Solution


i can find the force but i cannot find the distance, i found that the force is 32790N but i am stuck after that

Welcome to the PF.

Please show in detail your calculations so far. How did you get that number? You are given a force F and a mass m, use the equation you wrote to calculate the acceleration (deceleration in this case). How can you use the deceleration to figure out the time until the car stops?
 
berkeman said:
Welcome to the PF.

Please show in detail your calculations so far. How did you get that number? You are given a force F and a mass m, use the equation you wrote to calculate the acceleration (deceleration in this case). How can you use the deceleration to figure out the time until the car stops?
well first i found the force by multiplying m and a, then i subtracted the friction force which is 288n. i got the force as 32790 and this is where i got stuck. i thought the acceleration is 22.2m/s^2?
 
rmalski said:
well first i found the force by multiplying m and a, then i subtracted the friction force which is 288n. i got the force as 32790 and this is where i got stuck. i thought the acceleration is 22.2m/s^2?

You are given Force and mass, not acceleration a. You are given the initial velocity of 22.2m/s, which you will use after you calculate the acceleration to figure out how long it takes to stop.
 
ok that's where i messed up, so the acceleration is 288/1490 which is .193m/s^2?
 
ok i found it thank you
 
Great! :-)

Now post your other thread, unless you've figured it all the way out too... :-)
 
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