Which of the following potential energy curves in Fig. cannot possibly describe the elastic collision of two billiard balls ? Here $r$ is the distance between centres of the balls.

Open in App

Solution

Step 1: The potential energy of a system of two masses is inversely proportional to the distance $(r)$ between them, i.e.,
$V (r) a \frac{1}{r}$ .

Step 2: So, when the two billiard balls come in contact with each other their $P . E .$ become zero i.e. $f o r r = R + R = 2 R; V (r) = 0$ .

Out of the given graphs, the curve shown in the graph $(v)$ it is clear that $V (r) = 0 f o r r = 0$ . Therefore, all other curves cannot possibly describe the elastic collision of two billiard balls.

Suggest Corrections

Similar questions

Q. Which of the following potential energy curves in Fig. 6.18 cannot possibly describe the elastic collision of two billiard balls ? Here r is the distance between centres of the balls.

Q. Which of the following potential energy curves in the above figures cannot possibly describe the elastic collision of two billiard balls? Here

r

is the distance between centres of the balls.

Answer carefully, with reasons:

(a) In an elastic collision of two billiard balls, is the total kinetic energy conserved during the short time of collision of the balls (i.e. when they are in contact)?

(b) Is the total linear momentum conserved during the short time of an elastic collision of two balls?

(d) If the potential energy of two billiard balls depends only on the separation distance between their centres, is the collision elastic or inelastic? (Note, we are talking here of potential energy corresponding to the force during collision, not gravitational potential energy).

Answer carefully, with reasons :

(a) In an elastic collision of two billiard balls, is the total kinetic energy conserved during the short time of collision of the balls (i.e. when they are in contact) ?

(b) Is the total linear momentum conserved during the short time of an elastic collision of two balls ?

Q. Two identical ball bearings in contact with each other and resting on a frictionless table are hit head-on by another ball bearing of the same mass moving initially with aspeed V. If the collision is elastic, which of the following (Fig. 6.14) is a possible result after collision ?

Join BYJU'S Learning Program