Holooly Plus Logo
Holooly Plus Logo

Question 1.3: The Weight of One Pound-Mass Using unity conversion ratios, ...

The Weight of One Pound-Mass

Using unity conversion ratios, show that 1.00 lbm weighs 1.00 lbf on earth (Fig. 1–13).

The Blue Check Mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

A mass of 1.00 lbm is subjected to standard earth gravity. Its weight in lbf is to be determined.
Assumptions Standard sea-level conditions are assumed.
Properties The gravitational constant is g = 32.174 ft/s².

Analysis We apply Newton’s second law to calculate the weight (force) that corresponds to the known mass and acceleration. The weight of any object is equal to its mass times the local value of gravitational acceleration. Thus,

W=m g=(1.00 lbm )\left(32.174 ft / s ^{2}\right)\left(\frac{1 lbf }{32.174 lbm \cdot ft / s ^{2}}\right)= 1 . 0 0 lbf

Discussion Mass is the same regardless of its location. However, on some other planet with a different value of gravitational acceleration, the weight of 1 lbm would differ from that calculated here.

Related Answered Questions

Analyzing a Multifluid Manometer with EES Reconsider the multifluid manometer discussed in Example 1–7 and replotted in Fig. 1–61. Determine the air pressure in the tank using EES. Also determine what the differential fluid height h3 would be for the same air pressure if the mercury in the last

Verified Answer:
The pressure in a water tank is measured by a mult...

Hydrostatic Pressure in a Solar Pond with Variable Density Solar ponds are small artificial lakes of a few meters deep that are used to store solar energy. The rise of heated (and thus less dense) water to the surface is prevented by adding salt at the pond bottom. In a typical salt gradient solar

Verified Answer:
The variation of density of saline water in the gr...

Measuring Atmospheric Pressure with a Barometer Determine the atmospheric pressure at a location where the barometric reading is 740 mm Hg and the gravitational acceleration is g = 9.81 m/s^2. Assume the temperature of mercury to be 10°C, at which its density is 13,570 kg/m^3.

Verified Answer:
The barometric reading at a location in height of ...

Measuring Pressure with a Multifluid Manometer The water in a tank is pressurized by air, and the pressure is measured by a multifluid manometer as shown in Fig. 1–49. The tank is located on a mountain at an altitude of 1400 m where the atmospheric pressure is 85.6 kPa. Determine the air pressure

Verified Answer:
The pressure in a pressurized water tank is measur...

Measuring Pressure with a Manometer A manometer is used to measure the pressure in a tank. The fluid used has a specific gravity of 0.85, and the manometer column height is 55 cm, as shown in Fig. 1–46. If the local atmospheric pressure is 96 kPa, determine the absolute pressure within the tank.

Verified Answer:
The reading of a manometer attached to a tank and ...

Absolute Pressure of a Vacuum Chamber A vacuum gage connected to a chamber reads 5.8 psi at a location where the atmospheric pressure is 14.5 psi.

Verified Answer:
The gage pressure of a vacuum chamber is given. Th...

Solving a System of Equations with EES The difference of two numbers is 4, and the sum of the squares of these two numbers is equal to the sum of the numbers plus 20. Determine these two numbers.

Verified Answer:
Relations are given for the difference and the sum...

Effect of Piston Weight on Pressure in a Cylinder The piston of a vertical piston–cylinder device containing a gas has a mass of 60 kg and a cross-sectional area of 0.04 m^2, as shown in Fig. 1–54. The local atmospheric pressure is 0.97 bar, and the gravitational acceleration is 9.81 m/s^2.

Verified Answer:
A gas is contained in a vertical cylinder with a h...

Expressing Temperature Rise in Different Units During a heating process, the temperature of a system rises by 10°C. Express this rise in temperature in K, °F, and R.

Verified Answer:
The temperature rise of a system is to be expresse...

Obtaining Formulas from Unit Considerations A tank is filled with oil whose density is ρ = 850 kg/m^3. If the volume of the tank is V = 2 m^3, determine the amount of mass m in the tank.

Verified Answer:
The volume of an oil tank is given. The mass of oi...