A car driving at an initial speed of 10.0 m/s accelerates on a straight road at 3.00 m/s^2. a) what is the speed of the car after one quarter of a mile? (1 mile =1.609km). B) the driver in part A slams on the brakes after reaching the quarter mile. If the car can decelerate at a rate of 4.50 m/s^2, what is the stopping distance of the car?

Respuesta :

Answer:

The speed of the car and the stopping distance are 50.13 m/s and 279.22 m.

Explanation:

Given that,

Initial speed = 10.0 m/s

Acceleration = 3.00 m/s^2

Distance [tex]d = \dfrac{1}{4}\times1.609[/tex]

[tex]d = 0.40225\ km=0.40225\times10^{3}\ m[/tex]

We need to calculate the speed of the car,

Using equation of motion

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

Where, u = initial velocity

v = final velocity

a = acceleration

Put the value in the equation

[tex]v^2=(10.0)^2+2\times3.00\times0.40225\times10^{3}[/tex]

[tex]v^2=2513.5[/tex]

[tex]v=50.13\ m/s[/tex]

(B). We need to calculate the stopping distance of the car,

Using equation of motion again

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

Here,initial velocity = 50.13 m/s

Final velocity = 0

Acceleration = -4.50 m/s²

Put the value in the equation

[tex]0=(50.13)^2-2\times4.50\times s[/tex]

[tex]s=\dfrac{(50.13)^2}{2\times4.50}[/tex]

[tex]s=279.22\ m[/tex]

Hence, The speed of the car and the stopping distance are 50.13 m/s and 279.22 m.