Chemistry Chegg Worksheet

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ENGR1540Worksheet16Chapter9.docx

NI 2

ENGR 1540 Worksheet 16 Chapter 9

1. How fast (in meters per second) must an iron ball with a mass of 56.6 g be traveling in order to have a kinetic energy of 15.75 J?

2. What is the kinetic energy of a single molecule of oxygen if it is traveling at 1.5×103 m/s?

3. Carry out the following conversions of energy units:

a. 14.3 Btu into calories

b. 1.4×105 cal into joules

c. 31.6 mJ into Btu

4. According to Figure 9.2, the total energy supply in the United States in 2011 was 107.66×1015 Btu. Express this value in joules and in calories.

5. If a machine does 4.8×103 kJ of work after an input of 7.31×104 kJ of heat, what is the change in internal energy for the machine?

6. Calculate

a. q when a system does 54 J of work and its energy decreases by 72 J

b. ΔE for a gas that releases 38 J of hear and has 102 J of work done on it

7. State the first law of thermodynamics briefly in your own words.

8. Which system does more work:

a. ΔE=-436 J, q=400 J

b. ΔE=317 J, q=347 J

9. In which case is heat added to the system:

a. ΔE=-43 J, w=40 J

b. ΔE=31 J, w=34 J

10. For a car weighing 980 kg, how much work must be done to move the car 24 miles? Ignore factors such as frictional loss and assume an average acceleration of 2.3 m/s2.