Question

A cannon ball with a mass of 100 kg flies in horizontal direction with a speed of 600 m/s and strikes a railroad freight car filled with sand and initially at rest. The total mass of the car and sand is 25,600 kg. Find the speed of the car after the ball becomes embedded in the sand

Answer 1

2.334 m/s

Step-by-step explanation:

From law of conservation of linear momentum, the sum of initial and final momentum are equal. Since momentum p=mv where m is mass and v is speed. The initial mass of 100 kg has momentum but lorry is at rest hence no momentum.

Initial momentum

100*600=60000 kg.m/s

Final momentum

Both lorry and 100 kg exert momentum hence total mass is 100+25600=25700 kg

25700v=60000

V=60000/25700=2.3346303501945525291828793774319066147859 m/s

Rounded off, final velocity is 2.334 m/s