Given :N = 240 r.p.m. or = 2 x 240/60 = 25.14 rad/s ; Stroke = 300 mm = 0.3 m; m = 50 kg; ml = 37 kg; r = 150 mm = 0.15 m ; c = 2/3

**1. Balance mass required .**

Let B : Balance mass required, and b : Radius of rotation of the balance mass: 400 mm : 0.4 m

We know that B.b: (m 1 + c.m) r

B x 0.4 : 10.55 or B : 26.38 kg

**2. Residual unbalanced force **

Let Crank angle from top dead centre: 60° We know that residual unbalanced force.