If 10.4 m³ of air is compressed at a constant temperature to 5.1 m³ and 750 kPa gauge. Calculate how much work is done on the gas, assuming atmospheric pressure to be 100 kPa.
If 24,500 kJ of work is done in a cylinder when 115 kg of a perfect gas is expanded isothermally at 210°C from 0.035 m³ to 6.9 m³. Find the characteristic constant for this gas.
A gas at 1000 kPa gauge pressure and 30°C is transferred from a cylindrical vessel 1.5 m in diameter and 3 m long to another cylindrical vessel 2.5 m in diameter and 5 m long. If the new gauge pressure is 150 kPa, calculate the new temperature. Note: Assume atmospheric pressure to be 100 kPa for this calculation.
If 0.25 m³ of a gas at 4000 kPa gauge pressure is expanded until the gauge pressure is 500 kPa and the expansion is polytropic with n = 1.35. Find the final volume the gas will occupy. Note: Assume atmospheric pressure = 100 kPa
If 10.4 m³ of air is compressed at a constant temperature to 5.1 m³ and 750 kPa gauge. Calculate how much work is done on the gas, assuming atmospheric pressure to be 100 kPa.
A perfect gas is compressed under conditions of constant temperature to a volume of 30 m³. If the final pressure of the gas is 450 kPa gauge and the initial volume was 135 m³, what was the initial pressure? (Assume atmospheric pressure to be 101.3 kPa)
How much work is required to compress a gas polytropically from 195 kPa abs to 1600 kPa abs while reducing the volume to 0.8 m3? Use the value of "n" for this gas as 1.35.
If 1.45 m³ of air at 100 kPa abs and 12°C is compressed to 950 kPa abs while following the law PV1.34 = C. Taking R for air = 0.287 kJ/kg K, find the final volume of air and the mass of air compressed.
The mass of water that would be evaporated in one hour, from feedwater at 100°C into dry saturated steam at 100°C, by the same amount of heat that is required, per hour, to produce steam at the actual boiler condition is called the:
A boiler generates 10 kg of dry steam per 2 kg of coal burned. The heating value of the coal is 21,000 kJ/kg. The boiler produces 1500 kPa steam from 60°C feedwater. Calculate the efficiency.
Five kilograms of water at 100°C is changed to saturated steam having a final temperature of 120°C. Calculate the total amount of heat required in changing the water to steam.
A boiler generates 10 kg of dry steam per 2 kg of coal burned. The heating value of the coal is 21,000 kJ/kg. The boiler produces 1500 kPa steam from 60°C feedwater. Calculate the efficiency.
The mass of water that would be evaporated in one hour, from feedwater at 100°C into dry saturated steam at 100°C, by the same amount of heat that is required, per hour, to produce steam at the actual boiler condition is called the:
A 110 m long mild steel pipe in a refinery conveys oil at a maximum temperature of 140°C. In winter the plant is shut down, and the temperature of the pipeline drops to -25°C. Calculate the amount of shrinkage of the pipe.
If four plates of identical physical dimensions are subjected to the same temperature difference, the one made of which material will conduct the most heat?
A 110 m long mild steel pipe in a refinery conveys oil at a maximum temperature of 140°C. In winter the plant is shut down, and the temperature of the pipeline drops to -25°C. Calculate the amount of shrinkage of the pipe.
A 110 m long mild steel pipe in a refinery conveys oil at a maximum temperature of 140°C. In winter the plant is shut down, and the temperature of the pipeline drops to -25°C. Calculate the amount of shrinkage of the pipe.
A solid cylinder is 31 cm in diameter by 2.4 m long. It has the same mass as a lead cube with 0.5 m sides. What material is the cylinder likely made of?
The wheel-and-axle system below has dimensions d = 300 mm and R = 1.5 m. If the efficiency of the machine is 90%, find the mechanical advantage of the system.
A bar with a diameter of 494 mm and a length of 1.5 m has a square hole with 177.8 mm sides through its axis. If the mass of the bar is 2027.1 kg, find the relative density of this material.
A pile of coal that forms a perfect cone shape has a base area of 24 m² and a height of 15 m. Assuming the pile has 25 percent of void space, and that the density of the coal given is 1400 kg/m³, determine the mass of the coal in this pile.
A steel storage tank is 5 m long, 2 m wide and 4 m high. It is 60% full of ethylene glycol with a relative density of 1.1. What is the force load exerted by the fluid on one end?
A cylindrical tank has its axis vertical. It is 2 m in diameter and its mass is 800 kg. When it is filled to 2 m high with oil, the total mass is 5050 kg. What is the relative density of the oil?
A bar with a diameter of 494 mm and a length of 1.5 m has a square hole with 177.8 mm sides through its axis. If the mass of the bar is 2027.1 kg, find the relative density of this material.
A pile of coal that forms a perfect cone shape has a base area of 24 m² and a height of 15 m. Assuming the pile has 25 percent of void space, and that the density of the coal given is 1400 kg/m³, determine the mass of the coal in this pile.
The screw below has a pitch of a screw thread of 10 mm ("two start" thread). The handle is 300 mm long. An effort of 250 N is applied to the handle. If the efficiency of the jack due to the friction within the lifting threads is 50%, how many tonnes can it lift?
The ambient pressure is 100.78 kPa. The pressure gauge on a hot water boiler is showing 85 kPa. Determine the absolute pressure under which this boiler is operating.
A 5000 litre oil tank contains 60 litres of water. If the water is drained off and replaced with fresh oil of relative density 0.95, what is the change in the mass of the tank's contents?
A cylindrical tank has its axis vertical. It is 2 m in diameter and its mass is 800 kg. When it is filled to 2 m high with oil, the total mass is 5050 kg. What is the relative density of the oil?
The wheel-and-axle system below has dimensions d = 300 mm and R = 1.5 m. If the efficiency of the machine is 90%, find the mechanical advantage of the system.
The ambient pressure is 100.78 kPa. The pressure gauge on a hot water boiler is showing 85 kPa. Determine the absolute pressure under which this boiler is operating.
Three identical bolts are required to carry a total load of 6.75 t. If the stress allowed in the material is 55,900 kPa, calculate the minimum diameter of each bolt.
When a simply supported, horizontal beam has a load of 19,620 kN hanging from the center of the beam, each support (ignoring the mass of the beam itself) carries an equivalent mass of:
When considering a steel block subjected to a tensile force, we would find the stress in the block by: 1.Using the formula stress equals force divided by the area 2.Using the same formula we use to find stress in a block subjected to a compressive force 3.Using the same formula we use to find the shear stress in a bolt
A steel wire 6 mm in diameter is used for hoisting purposes in building construction. If 150 m of the wire is hanging vertically, and a load of 1 kN is being lifted at the lower end of the wire, determine the elongation of the wire. Ignore the mass of the wire itself. Assume that E = 200 GPa.
A diagram that shows the stress caused by forces acting perpendicular to the beam at every cross section along the length of a beam is called the _____ diagram.
Three identical bolts are required to carry a total load of 6.75 t. If the stress allowed in the material is 55,900 kPa, calculate the minimum diameter of each bolt.
When considering a steel block subjected to a tensile force, we would find the stress in the block by: 1.Using the formula stress equals force divided by the area 2.Using the same formula we use to find stress in a block subjected to a compressive force 3.Using the same formula we use to find the shear stress in a bolt
A steel tube is 7 m long and is 6 cm OD with a wall thickness of 4 mm. It hangs vertically with a load of 400 kg attached to its lower end. If the modulus of elasticity is 210 x 106 kPa, find the stress induced in pipe material.
A train travels at various speeds between several stations. From the train schedule the following information can be extracted about the different segments of the journey: 8 km traveled in 10 min., 14 km in 12 min., 16 km in 18 min., 12 km in 10 min. The average speed during the whole trip is:
In a speed test, a car traveling at 40 km/h increases its velocity uniformly for 4 seconds, while traveling the controlled distance of 100 m. Its acceleration in m/s² is:
In a speed test, a car traveling at 40 km/h increases its velocity uniformly for 4 seconds, while traveling the controlled distance of 100 m. Its acceleration in m/s² is:
A block of stone of 40 kg is hauled along a horizontal floor by a force inclined 20 degrees to the horizontal. If the coefficient of friction between the stone and the floor is 0.3, determine the effort required to just move the stone from rest.
A load of 750 kg just starts to move when the friction angle is 10°. What effort must be applied parallel to the horizontal surface to stop the motion of the block?
A body with a gravitational force of 2000 N is pulled along a horizontal surface at constant speed by a rope, which makes an angle of 20° above the horizontal. If the force on the rope is 150 N, the coefficient of sliding friction is:
Find the value and applied angle of the least force required to move a vessel, if the mass of the vessel is 1650 kg and the coefficient of friction is 0.49.
A sliding face of a slide valve of a steam engine is 150 mm by 300 mm, and the steam pressure on the back of the valve is 1200 kN/m². If the coefficient of friction is 0.02, what is the force required to move the valve?
A wooden box is loaded and its mass is 40 kg. A force of 150 N that just sets it in motion pulls it horizontally. Determine the coefficient of friction.
A load of 750 kg just starts to move when the friction angle is 10°. What effort must be applied parallel to the horizontal surface to stop the motion of the block?
Find the value and applied angle of the least force required to move a vessel, if the mass of the vessel is 1650 kg and the coefficient of friction is 0.49.
A man has a mass of 70 kg. What is the magnitude of the largest mass he can pull by a horizontal rope along a horizontal floor, if the coefficient of friction between the mass and the floor is 0.23, and that between his boot soles and the floor is 0.5?
A refrigerator with a mass of 150 kg sits on a perfectly level surface. It is pushed by a force of 350 N, acting upward at 30 degrees to the horizontal. If the coefficient of friction between the refrigerator and the surface is 0.25, what will happen to the refrigerator?
A. The refrigerator will start moving maintaining a steady speed as kinetic friction increases
B. The refrigerator will slide and continue to accelerate
C. The refrigerator will slide at a constant velocity
Find the value and applied angle of the least force required to move a vessel, if the mass of the vessel is 1650 kg and the coefficient of friction is 0.49.
A man has a mass of 70 kg. What is the magnitude of the largest mass he can pull by a horizontal rope along a horizontal floor, if the coefficient of friction between the mass and the floor is 0.23, and that between his boot soles and the floor is 0.5?
A body having a mass of 50.97 kg is pulled along a horizontal flat surface at a constant speed by a force of 180 N, which makes an angle of +30° with the horizontal. Find the coefficient of kinetic friction for the surfaces.
A load of 750 kg just starts to move when the friction angle is 10°. What effort must be applied parallel to the horizontal surface to stop the motion of the block?
A cylindrical tank with a vertical axis is 0.6 m in diameter. The oil level falls 20 cm in 17 days. Calculate the quantity of oil used per day in litres.
A reinforced concrete beam requires a cross-sectional area of reinforcing steel equal to 25 cm². If 2 cm diameter steel rods are used, how many will be required?
Calculate the number of 8 cm diameter tubes that can be attached to a circular tube sheet of a heat exchanger that is 1.0 m in diameter. Assume that 50% of the sheet area is used for spacing between the tubes.
A cylindrical tank with a vertical axis is 0.6 m in diameter. The oil level falls 20 cm in 17 days. Calculate the quantity of oil used per day in litres.
The top end of a 12 m long ladder rests on a vertical wall. The foot of the ladder is 3 m away from the base of the wall. Find the angle of inclination of the ladder.
A packaged boiler is to be unloaded from a flat car. The bed of the flat car is 2 m above the ground. What length of skids is necessary if the skids are to make an angle of 25 degrees with the ground?