# Chapter 1 Lecture Problems

## Density

1. At an altitude of 40 km the density of air is 4.3 gm/m3. What is the mass of 537 m3 of air at this altitude.
2. At an altitude of 10 km the same mass of air from above has a volume of only 5.433 m3. What is the density of this air?
Solutions

## Conversions

1. The temperature of liquid nitrogen, LN2, is -195 °C. Convert this to Kelvin and °F
2. Normal body temperature is 98 °F. Convert this temperature to °C and Kelvin.
3. Convert 15.4 cm into inches, given that 1 inch is defined as 2.54 cm.
4. Convert 3.46x104 cm into miles given the following conversion factors. 2.54 cm = 1 in; 1 ft = 12 in; 1 yd = 3 ft; 1 mi = 1760 yd.
5. Convert 55 miles per hour into meters per second.
Solutions

## Significant Digits

1. Place two sticks end to end. The length of the first stick is measured with a meter stick as 59.3 cm. The second stick is measured with a micrometer as 5.4895 cm. What is the total length?
2. Change length of second stick to 5.1594 cm. What is the total length?
3. Measure the length of the first stick with a better ruler, as 59.394 cm. What is the total length of the two sticks?
4. You are given a rectangular piece of metal. Using different devices you measure the following dimensions: Length 25.125 inches, Width 5.3 cm, Thickness 1.3458 mm. What is the volume of this piece?
5. Problem Solving. While driving across South Dakota, I looked down at the odometer in my truck and started a stop watch at the same time. The odometer read: 129356.4. Some time later I stopped the watch and looked at the odometer again. The odometer read: 129469.3 and the stopwatch read 94 min, 15.24 sec. What was my speed in miles per hour, kilometers per hour and meters per second?

1. Marathon Problem from Zumdahl