Integrated Concepts A certain heat lamp emits 200 W of mostly IR radiation averaging 1500 nm in wavelength. (a) What is the average photon energy in joules? (b) How many of these photons are required to increase the temperature of a persons shoulder by 2.0C , assuming the affected mass is 4.0 kg with a specific heat of 0.83 kcal/kg C . Also assume no other significant heat transfer. (c) How long does this take?

ilami (ki2628) – Homework #2 – reichl – (55945) 1 This print-out should have 18 questions. Multiple-choice questions may continue on 003 (part 3 of 3) 10.0 points the next column or page – ﬁnd all choices What is the position at 2 seconds before answering. Correct answer: 19 m. 001 (part 1 of 3) 10.0 points Explanation: Consider the plot below describing motion along a straight line with an initial position of 10 m. Let : x 0 10 m. 9 b 9 b 8 8 7 7 6 6 5 5 4 4 3 b velocity (m/s) 3 b 2 2 1 1 0 b b 0 b b b −1 b velocit1 (m2s) 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 −1 b