Question

What is the change in momentum of a car weighing 1500kg when its speed increases from 36km/h to 72km/h uniformly.

Answer 1

Mass of car = 1500kg
Initial velocity =36km/h
Initial linear momentum = mu
= 1500×36

=54000kgkmh-1
Final velocity =72km/h
Final linear momentum = mv
= 1500×72
= 108000 kgkmh-1
Change in momentum = mv-mu
=108000-54000
=54000kgkmh-1
Or 15000kgms-1

Answer 2

Answer:

mass of car = 1500 kg

initial velocity (u) = 36km/h

=36×5/18 = 10m/s

final velocity (v) = 72km

= 72×5/18 = 20m/s

Change in momentum = final velocity - initial velocity

= mv - mu {using values }

= m (v-u) m = 1500 kg

= 1500 (20-10) u = 10 m/s

= 1500 × 10 v = 20 m/ s

= 15000 kg m/s ans.