Acar traveling 23 m/s begins to decelerate at a constant rate of 5 m/s^2 . after how many seconds does the car come to a stop? (use symbolic notation and fractions where needed.)

t = 4.6 s

Explanation:

given,

initial velocity of the car = 23 m/s

declaration rate of car = 5 m/s²

final velocity of the car = ?

time taken to stop the car = ?

using equation of motion to solve the question

v = u + a t

v is final velocity

u is the initial velocity

0 = 23 - 5 t

we have used negative sign because there is deceleration

5 t = 23

t = 4.6 s

time taken to stop the car is equal to t = 4.6 s

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s