Starting with the canonical commutation relations for position and momentum a) evaluate l , d ili, pi, where l1-tijkr, pk b) evaluate [l,. lj] c) evaluate [li. 2] and [l,.p] d) show that the hamiltonian ril an h=l, v(r) 2m commutes with l hint: be careful with the indices!

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?

The frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?

A1500 w electric heater is plugged into the outlet of a 120 v circuit that has a 20 a circuit breaker. you plug an electric hair dryer into the same outlet. the hair dryer has power settings of 600 w, 900 w , 1200 w, and 1500 w. you start with the hair dryer on the 600 w setting and increase the power setting until the circuit breaker trips. under what setting does the circuit breaker trip.