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 General Physics General Physics Help Forum Jul 15th 2018, 01:36 PM #1 Junior Member   Join Date: Jul 2018 Posts: 5 question A car with a mass of 1000 kg traveled in a straight line at a speed of v0 = 21m / sec. Once t = 0 the driver was moved to neutral and continued to travel in a straight line. From this moment until the car stopped its speed was measured and found suitable for the function v (t) = 10tan (--5⋅10-3t) m / sec (When time is measured in seconds and the argument of the tan function is in radians) A. Find the value of the constant. B. Find the equivalent force that acts on the car as dependent on time and show that it can be displayed as F = -αv2-f0 as the momentary velocity of the car. Find the constant values ​​α and f0 (can be used for identity 1 + tan2 = = 1cos2)) third. Find the total distance that the car will go until it stops (hint: use u = cosx and additional positions as needed to calculate the integral)   Jul 16th 2018, 01:19 AM #2 Senior Member   Join Date: Jun 2016 Location: England Posts: 963 We are not a homework answering service. If you have tried, and give us your thoughts so far, we can point out where you are going wrong. We will also try to provide hints and suggestions. We will not just do your homework for you. It is important for your tutor to know how well (or how badly) you are managing with your homework, A good tutor will use this information to provide additional assistance where you are struggling. If you just hide your difficulties by getting someone else to do your homework for you, then your tutor will never know that you are struggling. topsquark likes this. __________________ ~\o/~   Jul 16th 2018, 04:41 AM   #3
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 A car with a mass of 1000 kg traveled in a straight line at a speed of v0 = 21m / sec. Once t = 0 the driver was moved to neutral and continued to travel in a straight line. From this moment until the car stopped its speed was measured and found suitable for the function v (t) = 10tan (--5⋅10-3t) m / sec
What does the "--" mean here? Is that just a negative? If so just one - would do. And is "5⋅10" "5 times 10"? If so why not just write "50"?
That is, is v(t)= 10 tan(-50- 3t)? Or do you mean v(t)= 10 tan(-5(10- 3t)) but forgot the parentheses?

 (When time is measured in seconds and the argument of the tan function is in radians) A. Find the value of the constant.
What constant are you referring to? There is no undetermined constant in your formula.

 B. Find the equivalent force that acts on the car as dependent on time and show that it can be displayed as F = -αv2-f0 as the momentary velocity of the car.
Force equals mass times acceleration. Find the acceleration by differentiating the velocity function and multiply by the mass of the car, 1000 kg. And, again, if v2 is intended to mean "v squared", write "v^2".

 Find the constant values ​​α and f0 (can be used for identity 1 + tan2 = = 1cos2))
Surely you do not mean "tan(2)" and "cos(2)"! Use ^ to indicate exponents. And do not write functions without their arguments: 1+ tan^2(x). 1+ tan^2(x) is equal to sec^2(x) which apparently are writing as 1/cos^2(x) but forgot the "/"!

 third. Find the total distance that the car will go until it stops (hint: use u = cosx and additional positions as needed to calculate the integral)
The total distance the car will go is $\displaystyle \int_0^T v(t)dt$ where T is the value you calculated in (A).

("A", "B", and "third"?)

Last edited by HallsofIvy; Jul 17th 2018 at 06:31 AM.  Tags question Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode