48. An ion's position vector is initially F = 5.01 - 6.0j + 2.0k, and 10 s and later it is r = -2.01 +8.0j - 2.0k, all in metres. In unit-vector notation, what is its Vava during the 10 s?

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.

Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600

Aheat engine that operates on a carnot cycle has an efficiency of 0.420 when its low-temperature reservoir is at 10 ∘c.part aby how many degrees celsius must you increase the temperature of the high-temperature reservoir to increase the efficiency to 0.600 if you continue to use the same low-temperature reservoir?