Question

It was once recorded that a Jaguar left skid marks that were 320 m in length. Assuming that the Jaguar skidded to a stop with a constant acceleration of -2.2 m/s2 , determine the speed of the Jaguar before it began to skid.

Answer 1

The speed of the Jaguar before it began to skid : 32.532 m/s

Further explanation

Linear motion consists of 2: constant velocity motion with constant velocity and uniformly accelerated motion with constant acceleration

An equation of uniformly accelerated motion

`\large {\boxed {\bold {x=xo+vo.t+\frac {1} {2} at ^ 2}}}`

vt = vo + at

vt² = vo² + 2a (x-xo)

x = distance on t

vo / vi = initial speed

vt / vf = speed on t / final speed

a = acceleration

`\tt v_f=v_i-at\rightarrow v_f=0(stop),a-=deceleration\\\\0=v_i-2.2.t\\\\v_i=2.2t\\\\x=v_i.t-(1)/(2)at^2\\\\x=2.2.t^2-(1)/(2)at^2\\\\320=2.2t^2-(1)/(2)2.2t^2\\\\320=2.2t^2-1.1t^2\\\\320=1.1t^2\Rightarrowt=17.06~s\\\\v_i=2.2* 17.06\\\\v_i=37.532~m/s`