A car moving with an initial speed of 25 m/s slows down to a speed of 5 m/s in 10 seconds Calculate a) the acceleration of the car.? b) the distance covered by the car

Respuesta :

Answer :

(a) The acceleration  of the car is, [tex]-2m/s^2[/tex]

(b) The distance covered by the car is, 150 m

Explanation :  

By the 1st equation of motion,

[tex]v=u+at[/tex] ...........(1)

where,

v = final velocity = 5 m/s

u = initial velocity  = 25 m/s

t = time = 10 s

a = acceleration  of the car = ?

Now put all the given values in the above equation 1, we get:

[tex]5m/s=25m/s+a\times (10s)[/tex]

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

The acceleration  of the car is, [tex]-2m/s^2[/tex]

By the 2nd equation of motion,

[tex]s=ut+\frac{1}{2}at^2[/tex] ...........(2)

where,

s = distance covered by the car = ?

u = initial velocity  = 25 m/s

t = time = 10 s

a = acceleration  of the car = [tex]-2m/s^2[/tex]

Now put all the given values in the above equation 2, we get:

[tex]s=(25m/s)\times (10s)+\frac{1}{2}\times (-2m/s^2)\times (10s)^2[/tex]

By solving the term, we get:

[tex]s=150m[/tex]

The distance covered by the car is, 150 m