In: Physics
... Instead of two blocks and one pulley, let
(a) Draw a complete free-body diagrams as shown in figure 2 below ::
(b) equation(s) that come from the free-body diagrams is given as ::
1. First, for mass m1 : FNet, 1 = T1 - Ff1 = m1 a
2. tensions at T1 and T2 : net = R T2 - R T1 = I
3. forces on m2, the mass on the incline : Fnet = w2 sin 30o - Ff2 - T2 = m2 a
4. equations with three unknowns, T1, T2, and a : T1 - m1 g = m1 a
5. T2 - T1 = ( I / R) = ( I / R ) ( a / R ) = ( I / R2 ) a
6. T1 - (0.36) (2.0 kg) (9.8 m/s2) = (2.0 kg) a
7. T2 - T1 = [ 0.3125 kg m2 / (0.25 m)2 ] a = 5 kg a
(c) equations that relate the various accelerations to each other is given as ::
1. FNet, 1 = T1 - Ff1 = m1 a
2. linear acceleration of the blocks is closely related to angular acceleration of the pulley : a = r
3. T1 - m1 g = m1 a
4. angular acceleration is related with acceleration : = a /r