In the figure, two blocks of masses m and 3m are linked by a light, inextensible rope that passes through an ideal pulley. Block m is tied to a spring with force constant k that joins it to the floor. Initially, the spring is in its equilibrium position and the entire system is at rest. a) Find the maximum distance x that the spring elongates if the system starts from rest.
b) What is the speed of the blocks when they have travelled half that distance?

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.