# Springs and motion of car

#### zachattackback

1. The problem statement, all variables and given/known data
A car towing a 92 kg trailor with a spring between the car and the trailor. the accelertion of the car is .3. the spring constant is 2300
how far is the spring stretched

2. Relevant equations
Fs=kx

3. The attempt at a solution

Fs=kx
ma=kx
(92)(.3)=2300x
x=.012m

i am not sure if that was legal

#### OlderDan

Homework Helper
1. The problem statement, all variables and given/known data
A car towing a 92 kg trailor with a spring between the car and the trailor. the accelertion of the car is .3. the spring constant is 2300
how far is the spring stretched

2. Relevant equations
Fs=kx

3. The attempt at a solution

Fs=kx
ma=kx
(92)(.3)=2300x
x=.012m

i am not sure if that was legal
It is legal, but it rests on several assumptions.

1) That the units of a are m/s²

2) That the units of k are N/m

3) That the acceleration of the trailor is constant- the length of the spring is constant. In reality, it would not be if the car started moving with constant acceleration at some point in time.

#### zachattackback

thanks for the help

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