Question

A 5kg object is hanging by a 1.5m wire when it is suddenly hit by a 3kg missile traveling horizontally at 12m/s. The missile embeds itself in the object during the collision. What is the tension in the rod immediately after the collision?

Answer 1

$mv=mv'+MV$

$mv^2/2=mv'^2/2+MV^2/2$ . So, have

$3\cdot12=3v'+5V$

$3\cdot12^2=3v'^2+5V^2\to$ $V=5.14\ (m/s)$

$F=ma\to F=m\cdot\frac{V^2}{r}=5\cdot\frac{5.14^2}{1.5}=88\ (N)$

$T=F+mg=88+5\cdot9.8=137\ (N)$ . Answer