Two lines:L₁: \(x = 5, \; \frac{y}{3 - \alpha} = \frac{z}{-2}\)L₂: \(x = \alpha, \; \frac{y}{-1} = \frac{z}{2 - \alpha}\)are coplanar. Then \(\alpha\) can take value(s):
A particle is moving in a straight line. The variation of position $ x $ as a function of time $ t $ is given as: $ x = t^3 - 6t^2 + 20t + 15 $. The velocity of the body when its acceleration becomes zero is: