A speeder passes a parked police car at a constant speed of 28.1 m/s. At that instant, the police car starts from rest with a uniform acceleration of 2.17 m/s 2 . How much time passes before the speeder is overtaken by the police car? How far does the speeder travel before being overtaken by the police car?

Respuesta :

Answer:

(A) after 12.94 sec speeder will be overtaken by police car

(B) speeder will travel 181.9377 m before coming to rest

Explanation:

We have given that speeder passes a parked police car with a constant speed of 28.1 m/sec

As the police car starts from rest so its initial velocity u = 0 m/sec

It is given that police car is travelling with a constant acceleration of [tex]2.17m/sec^2[/tex]

So acceleration a = [tex]2.17m/sc^2[/tex]

From first equation of motion v = u+at

So [tex]28.1=0+2.17\times t[/tex]

t = 12.94 sec

So after 12.94 sec speeder will be overtaken by police car

(b) From second equation of motion [tex]s=ut+\frac{1}{2}at^2[/tex]

[tex]s=0\times 12.94+\frac{1}{2}\times 2.17\times 12.94^2=181.9377m[/tex]

So speeder will travel 181.9377 m before coming to rest