A solid-fueled rocket can be made using a fuel grain with either a hole (a), or starred cavity (b), in the cross section. From experiment the engine thrust-time curves (T vs. t) for the same amount of propellant using these geometries are shown. Determine the total impulse in both cases. Given: { T }_{ 1a } = 4 lb , { t }_{ 1a } = 3 s , { T }_{ 1b } = 8 lb , { t }_{ 1b } = 6 s , { T }_{ 2a } = 6 lb , { t }_{ 1c } = 10 s , { t }_{ 2a } = 8 s , { t }_{ 2b } = 10 s