m1 = 0.4 kg, u1 = 4 ms-1 m2 = 0.6kg, u2 = 2 ms-1
∴ Total K E of system before collision
ki = \(\frac{1}{2}\)m1u12 + \(\frac{1}{2}\)m2u22
\(\frac{1}{2}\)× 0.4 × 42 + × 0.6 × 22
= 3.2 + 1.2 = 4.4J
∴ As collision is perfectly inelastic, the common velocity after collision v is given by
v =
= 2.8 ms-1
∴ Total K E of system after collision
kf = \(\frac{1}{2}\)(m1 + m2) v2 = \(\frac{1}{2}\)(1) × (2.8)2
= 3.92 J.
∴ Loss in K E = Δ K E = Δ K = Ki – Kf
= 4.4 – 3.92 J
= 0.48 J.