Question

a motor car of mass 1200kg is moving with velocity of 90km/h its velocity is slow down to 18km/h in 4s by an unbalanced external force .calculate the acceleration and change in momentum ​

Answer 1

Explanation:

Initial velocity =90km/h=90×5/18m/s=25m/s

Final velocity =18km/h=18×5/8m/s=5m/s

Acceleration =(final velocity - initial velocity) /time taken

=(25-5)/4=5m/s²

Now,

Change in momentum =m(final velocity - initial velocity)

=1200×(25-5)=24000kgm/s

Force=change in momentum /time

=24000/4

=6000N