Question

A car starts from rest and moves along the x axis with a constant acceleration of 5m/s 2 for 8 seconds. if it then continues to move with a constant velocity , what distance will the car cover in 12seconds since it starts from rest?

Answer 1

lets divide the qstn into 2 parts..

(1) the distance it travelled in the frst 8 sec

(2) the distance it travld inte next 4 secs..that is in total 12 sec.

(1) given,

  u=0

a=5m/s^2

t=8s

using the eqn s=ut+1/2 at2,

s=0+(1/2)*5*(8^2)

s=160m..................this s d distnce travelled in 8 sec.

now while considering the 2nd part the final velocity in the frst becomes the initial in the sec.

find the final velocity. v=u+at..(not sure abt dis eqn....sry.)

u get v=40m/s.

in the secnd prt it is said that the body moves with uniform velocity. ie a=0
using the eqn s=ut+1/2at2,

u get s=(40*4)+0

s=160m.

thrfore the total distance travelled equals 160+160

=320m....

Please mark it as brainiest answer ....