Question

For each of the following collisions, argue for or against the collision being at least approx-

imately isolated. In each case the system is indicated. If the collision is not isolated then

explain what external force(s) cause it to not be isolated.

(a) A truck runs into a concrete barrier. The barrier is fastened to the ground by steel rods,

but the steel rods snap during the collision so that the barrier moves. [system: truck

and concrete barrier]

(b) An asteroid crashes into a planet leaving a big crater. [System: asteroid and planet

(c) A common midway game is to throw balls to knock bottles over. Suppose the person

operating the game isn’t very honest and they have stuck the bottles to the surface

with putty. A ball collides with a bottle and bounces off. The bottle remains standing.

[System: ball and bottle

Answer 1

(a) A truck runs into a concrete barrier. The barrier is fastened to the ground by steel rods,

but the steel rods snap during the collision so that the barrier moves. [system: truck

and concrete barrier] this system is not a isolated system because external forces acts on concrete barrier due to steel rods.

​(b) this is a isolated system because bo external forces acts on given two objects. it will be an inelastic collision.

(c) this is an isolated system where one mass (a ball) collides with other mass (bottle+putty), to give an elastic collision.