Answer to Question #270977 in Mechanics | Relativity for bookaddict

Question

a car is traveling on a straight road at 19 m/s. the driver sees a bird standing in the road 38 meters ahead and applies the brakes, giving constant deceleration of 5 m/s^2.

how far away is the driver from the bird when he stops( assuming the bird doesn't move)

Answer 1

$v=0$ m/s , when he stops

$v_0=19$ m/s, initial velocity

$a=-5$ m/s$^2$ , constant deceleration

$\Delta x=\frac{v^2-v_0^2}{2a}=\frac{0^2-19^2}{2\cdot (-5)}=36.1$ m

$38-36.1=1.9$ m

Answer: $1.9$ m from the bird.