A bicyclist is traveling at 2.0m/s then gets faster when traveling down a hill, reaching 19 m/s in only 3.5s. a) What was the acceleration of the rider, assuming it was constant for the ride? b) How long was this hill?

Respuesta :

Answer:

a. [tex]4.857m/s^2[/tex]

b.36.75 m

Explanation:

We are given that

Initial speed, u=2m/s

Final speed, v=19 m/s

Time, t=3.5 s

a.

We know that

Acceleration, a=[tex]\frac{v-u}{t}[/tex]

Using the formula

[tex]a=\frac{19-2}{3.5}[/tex]

[tex]a=\frac{17}{3.5}[/tex]

[tex]a=4.857m/s^2[/tex]

Hence, the acceleration of the rider, [tex]a=4.857m/s^2[/tex]

b.

We know that

[tex]v^2-u^2=2as[/tex]

Using the formula

[tex](19)^2-2^2=2\times 4.857s[/tex]

[tex]361-4=9.714s[/tex]

[tex]357=9.714s[/tex]

[tex]s=\frac{357}{9.714}[/tex]

[tex]s=36.75 m[/tex]

Length of hill=36.75m