Engineering Assignment

ENGR 112 HW#6 NAME________________________

1. An object has a mass of approximately 7895.2 grams and a

volume of 25.65 cubic feet. Determine the density of the object in

units of pounds-mass per cubic foot. Also determine the specific

gravity of the object.

2. Given the following Densities, what is the specific gravity of each?

a. 8.75 kg/L

b. 11.0 slugs/ft3

3. What is the weight of 8 liters of Toluene in units of newtons? Specific Gravity of Toluene = 0.865

4. A platinum bar of metal (5 centimeters by 18 centimeters by 4 centimeters) being transported by armored car is suspected of being fake, made from a less valuable metal. The bar is found to have a mass of 7.704 kilograms. If the specific gravity of platinum is 21.4, is the bar fake? Justify your answer.

5. A submersible is rated to withstand a hydrostatic pressure of 45 Megapascals [Mpa]. If sea water has a specific gravity of 1.03, how deep in units of kilometers [km] can the submersible descend before reaching this pressure limit?

6. An ideal gas in a 5.5-gallon container is at a temperature of 250 degrees Fahrenheit and a pressure of 5 atm. If the gas is Xenon (formula: Xe, molecular weight = 131.92 grams/mole), what is the mass of gas in the container in grams?

7. A 20-kg projectile traveling at 55 m/s is stopped by being shot into an insulated tank containing 250 kg of water. If the kinetic energy of the projectile is completely converted into thermal energy with no energy lost, how much will the water increase in temperature in units of degrees Celsius? The specific heat of water is 1 calorie/g-degree Celsius.

8. You need to purchase a motor that will lift a 1000lbm weight to a height of 50ft in under 120 seconds. All the motors you can find are 75% efficient. What is the minimum wattage on the motor you need to choose?