Two equal spheres and , each of mass , are in contact on a smooth horizontal table. A third sphere of same size as that of or but mass impinges symmetrically on them with a velocity and is itself brought to rest

The coefficient of restitution between the two spheres and (or between and ) is |
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a) |
b) |
c) |
d) |

Two equal spheres and , each of mass , are in contact on a smooth horizontal table. A third sphere of same size as that of or but mass impinges symmetrically on them with a velocity and is itself brought to rest

The coefficient of restitution between the two spheres and (or between and ) is |
|||||||

a) |
b) |
c) |
d) |

1 Answer

127 votes

**(a)**

velocity of sphere before impact. As the spheres are identical, the triangle formed by joining their centres is equilateral. The spheres and will move in direction and after impact making an angle of with the original lines of motion of ball

Let be the speed of the ball and after impact

Momentum conservation gives

(i)

From Newton’s experimental law, for an oblique collision, we have to take components along normal, i.e., along for balls and

Combining Eqs. (i) and (ii), we get

127 votes

127