A motorcycle is known to accelerate from rest to 190km/h in 402m.
Considering the rate of acceleration is constant, how should I go about calculating the acceleration rate and the time it took the bike to complete the distance?
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$\begingroup$ Try v=u+at for acceleration. $\endgroup$– aries0152Commented Oct 22, 2012 at 12:16
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$\begingroup$ But I don't know how long it took the bike to cover the stretch. I only know Vi (0), Vf (190km/h), and d (402m). $\endgroup$– pilauCommented Oct 22, 2012 at 12:33
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$\begingroup$ You are correct that you need more than just that equation. The other kinematic equation you might want to use is $x=1/2 a t^2$, which uses the fact that you started from rest and had a constant acceleration. I'd advise reading a basic kinematics tutorial online. $\endgroup$– Alan RomingerCommented Oct 22, 2012 at 15:32
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$\begingroup$ I advise reading ja72's answer below ;) $\endgroup$– pilauCommented Oct 22, 2012 at 15:47
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1 Answer
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For constant acceleration, you have two equations that you need to solve for time $t$ and acceleration $a$.
$$x=\frac12at^2$$ $$v=at$$
It is up to you from here.
$$402\ \mathrm m=\frac12at^2$$ $$\left(190\ \mathrm{\frac{km}h}\right)\left(\frac{1000\ \mathrm{\frac m{km}}}{3600\ \mathrm{\frac sh}}\right)=\left(52.777\ \mathrm{\frac ms}\right)at$$
answered Oct 22, 2012 at 13:47