Mechanical Engineering Answers

The acceleration of high-speed aircraft is sometimes expressed in g’s (in multiples of the standard acceleration of gravity). Determine the net upward force, in N that a 90 kg man would experience in an aircraft whose acceleration is 6 g’s.

The force of attraction between two masses m1 and m2, having dimensions that are small compared with their

separation distance R, is given by Newton’s third law, F=Gm1m2/R2, where G=6.67259x10-11 N-m2/kg2. What

is the total gravitational force that the sun (1.97x1030 kg) and the earth (5.95x1024 kg) exert on the moon (7.37x1022 kg) at

an instant when the earth, moon, and sun form a 90° angle? The earth-moon and sun-moon distances are 380x103 km

and) 150x106 km, respectively

The acceleration of gravity is given as a function of elevation above sea level by the relation g=9.81-3.32x10-6 h, with h measured in meters. What is the weight

of an airplane at 10km elevation when its weight at sea level is 40 kN?

Convert a chromel-alumel thermocouple measurement of 3.100 millivolts (mV) to degress Celsius. For a chromel-alumel type K thermocouple, 3.100 mV is between the entries of 2.667 (at 150°F) and 3.819 (at 200°F). Assume a linear relation between the two.

A vertical piston-cylinder device has a piston diameter of 11 cm and piston mass of 40 kg. the atmospheric

pressure is 0.10Mpa and the local gravity is 9.79 m/s2. Determine the absolute pressure of the gas within the device.

A 7 lbm piece of steel is subjected to a vertical force of 8 lbf. The local gravity is 31.1 ft/s2, and frictional effects are neglected. Determine the acceleration of the mass if the external vertical force is (a) downward, (b) upward in ft/s2.

A bell jar 250mm in diameter sits on a plate and is evacuated until a vacuum of 700mmHg exists. The local barometer reads 760mmHg. Find the absolute pressure inside the jar, and determine the force required to lift the jar off the

plate. Neglect the weight of the bell jar.

Two liquid streams are pouring in a container, 8 in. diameter and 15in. high. The mass flow rate of stream A is 1.2

lb/sec and the volume flow rate of B is 0.035 ft3/s. If the specific gravities of A and B are 1.1 and 0.9, respectively, in how many seconds will the container be filled? What is the gage and absolute pressure at the bottom of the filled tank in psia.

The gage pressure of a gas inside a tank is 25kPa. Determine the vertical height, in meters, of liquid within a manometer attached to the system if the fluid at room temperature is (a) water, (b)mercury (ρ=13,600kg/m3), and (c) an oil with a specific gravity of 0.88 and g=9.75 m/s2

A vertical storage tank initially contains water (ρ=1000kg/m3) at a depth of 4m. Immiscible oil with a specific gravity of 0.88 is added until the total liquid height is 10m. If the barometer pressure is 97.2kPa and g=9.80m/s2, determine the

absolute pressure at the bottom of the water, in kPa and bars.