## Conceptual Physics (12th Edition)

a. The telescope's angular momentum is conserved (does not change) because no net external torque acts on it. The angular momentum is mvL. $$(m)(v_{initial})(L) = (m)(v_{new})(0.33L)$$ $$v_{new} =(v_{initial})\frac{L}{0.33L} = 3.0 v_{initial}$$ b. Plug in values. $$v_{new} =( 1.0 \frac{m}{s})\frac{L}{0.33L} = 3.0 \frac{m}{s}$$