A person driving a car suddenly applies the brakes. The car takes 7.0 s to come to rest while traveling 26 m at constant acceleration. What was the initial speed of the car (in m/s)?

Respuesta :

Answer:

7.43 m/s

Explanation:

Time taken for car to stop = 7.0 s

distance traveled before coming to rest = 26 m

Final speed of the car = 0 m/s (since it stops)

initial speed of the car = ?

To get the final speed, we use the equation

s = [tex]\frac{1}{2}t(u + v)[/tex]

where

s is the distance traveled before stopping

u is the initial speed = ?

v is the final speed = 0 m/s

t is the time = 7 s

substituting values, we have

26 = [tex]\frac{1}{2}*7*(u + 0)[/tex]

26 = 3.5u

u = 26/3.5 = 7.43 m/s