All Matches

Solution Library

Expert Answer

Textbooks

Search Textbook questions, tutors and Books

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Tutors
Study Help
Hire a Tutor
AI Study Help New

Search
Sign In
Register

study help
engineering
mechanical engineering

Questions and Answers of Mechanical Engineering

Air rushes in to fill an evacuated insulated tank as the valve is opened. Determine the interactions and the sign of Q and Wext, if any, treating(a) The tank as the system.(b) The tank and the
On a hot day, a student turns on the fan and keeps the refrigerator door open in a closed kitchen room, thinking that it would cool down the hot kitchen. Treating the room as a closed insulated
An external force drags and accelerates a rigid body over a surface. Treating the body as a thermodynamic system, determine the sign (positive: 1; negative: -1; none: 0) of (a) Wext (b) Q across its
During the free fall of a rigid body (system), identify the interactions between the system and its surroundings.
An electric adapter for a notebook computer (converting 110 volts to 19 volts) operates 10oC warmer than the surrounding temperature. Determine the sign (positive: 1; negative: -1; none: 0) of (a)
A block of ice dropped into a tank of water as shown (see accompanying animation) begins melting. Identify the interactions for the (a) Ice as a system. (b) Water in the tank as a system. (c) Water
A gas trapped in an insulated piston-cylinder assembly expands as it is heated by an electrical resistance heater placed inside the cylinder. Treating the gas and the heater as the system, identify
A piston-cylinder device contains superheated vapor at atmospheric pressure. The piston is pulled by an external force until the pressure inside drops by 50%. Determine the sign (positive: 1;
Air with a density (ρ) of 1 kg/m3 flows through a pipe of diameter 20 cm at a velocity of 10 m/s. Determine (a) The volume flow rate in L/min (b) Mass flow rate in kg/min. Use the PG flow state
Steam flows through a pipe of diameter 5 cm with a velocity of 50 m/s at 500 kPa. If the mass flow rate of steam is measured at 0.2 kg/s, determine (a) The specific volume (v) of steam in m3/kg. (b)
Water flows through a variable-area pipe with a mass flow rate of 10,000 kg/min. Determine the minimum diameter of the pipe if the flow velocity is not to exceed 5 m/s. Assume density (ρ) of water
A mixture of water (ρ = 1000 kg/m3) and oil (ρ = 800 kg/m3) is flowing through a tube of diameter 2 cm with a velocity of 4 m/s. The mass flow rate is measured to be 1.068 kg/s. Determine (a) The
Air flows through a pipe of diameter 10 cm with an average velocity of 20 m/s. If the mass flow rate is measured to be 1 kg/s, (a) Determine the density (ρ) of air in kg/m3. (b) What-if Scenario:
Air flows steadily through a constant-area duct. At the entrance the velocity is 5 m/s and temperature is 300 K. The duct is heated such that at the exit the temperature is 600 K.(a) If the specific
Hydrogen flows through a nozzle exit of diameter 10 cm with an average velocity of 200 m/s. If the mass flow rate of air is measured as 1 kg/s, determine (a) The density (ρ) of hydrogen at the exit
A horizontal-axis wind turbine has a diameter of 50 m and faces air coming at it at 20 miles per hour. If the density (ρ) of air is estimated as 1.1 kg/m3, determine the mass flow rate of air
Steam at 400oC enters a nozzle with an average velocity of 20 m/s. If the specific volume (v) and the flow area at the inlet are measured as 0.1 m2/kg and 0.01 m2 respectively, determine (a) The
A bucket of concrete with a mass of 5000 kg is raised without any acceleration by a crane through a height of 20 m. (a) Determine the work transferred into the bucket. (b) Also determine the power
Twenty 50 kg suitcases are carried by a horizontal conveyor belt at a velocity of 0.5 m/s without any slippage. If μs = 0.9. (a) Determine the power required to drive the conveyor. Assume no
A person with a mass of 70 kg climbs the stairs of a 50 m tall building. (a) What is the minimum work transfer if you treat the person as a system? Assume standard gravity. (b) If the energetic
A person with a mass of 50 kg and an energetic efficiency of 35% decides to burn all the calories consumed from a can of soda (140 Calories) by climbing stairs of a tall building. Determine the
The aerodynamic drag force Fd in kN on an automobile is given as Fd = 1/2000 cd A ρ V2 [kN], Where cd is the non-dimensional drag coefficient, A is the frontal area in m2, ρ is the density of the
The rolling resistance of the tires is the second major opposing force (next to aerodynamic drag) on a moving vehicle and is given by Fr = f W [kN] where f is the rolling resistance coefficient and W
Determine (a) the power required to overcome the aerodynamic drag and (b) rolling resistance for a truck traveling at a velocity of 120 km/h, if cd = 0.8, A = 10 m2, ρ = 1.2 kg/m3, f = 0.01, and m =
Determine (a) The power required to overcome the aerodynamic drag. (b) Rolling resistance for a bicyclist traveling at a velocity of 21 km/h, if cd = 0.8, A = 1.5 m2, ρ = 1.2 kg/m3, f = 0.01 and m =
Determine: (a) The work transfer involved in compressing a spring with a spring constant of 150 kN/m from its rest position by 10 cm. (b) What is the work done in compressing it further by another 10
An object with a mass of 200 kg is acted upon by two forces, 0.1 kN to the right and 0.101 kN to the left. Determine (a & b) the work done by the two faces. (c) The net work transfer as the system
A rigid chamber contains 100 kg of water at 500 kPa, 100oC. A paddle wheel stirs the water at 1000 rpm while an internal electrical resistance heater heats the water while consuming 10 amps of
The accompanying figure shows a body of mass 50 kg being lifted at a constant velocity of 1 m/s by the rope and pulley arrangement. Determine power delivered by the shaft.
A piston-cylinder device containing a fluid is fitted with a paddle wheel stirring device operated by the fall of an external weight of mass 50 kg. As the mass drops by a height of 5 m, the paddle
An insulated piston-cylinder device contains steam at 300 kPa, 200oC, occupying a volume of 1 m3, and having a specific volume of 0.716 m3/kg. It is heated by an internal electrical heater until the
A gas in a vertical piston-cylinder device has a volume of 0.5 m3 and a temperature of 400 K. The piston has a mass of 50 kg and a cross-sectional area of 0.2 m2. As the gas cools down to atmospheric
A man weighing 100 kg is standing on the piston head of a vertical piston-cylinder device containing nitrogen. The gas is now heated by an electrical heater until the man is slowly lifted by a height
A 10 m3 insulated rigid tank contains 20 kg of air at 25oC. An electrical heater within the tank is turned on which consumes a current of 5 Amps for 30 min from a 110 V source. Determine the work
A paddle wheel stirs a water tank at 500 rpm. The torque transmitted by the shaft is 20 N-m. At the same time an internal electric resistance heater draws 2 Amps of current from a 110 V source as it
An electric motor draws a current of 16 amp at 110 V. The output shaft delivers a torque of 10 N-m at a speed of 1500 RPM. Determine(a) The electric power transferred.(b) Shaft power.(c) The rate of
Air in a horizontal piston-cylinder assembly expands from an initial volume of 0.25 m3 to a final volume of 0.5 m3 as the gas is heated for 90 seconds by an electrical resistance heater consuming 1
An elevator with a total mass of 1500 kg is pulled upward using a cable (see Anim. 0-4-2) at a velocity of 5 m/s through a height of 300 m. (a) Determine the rate at which is work is transferred into
A vertical piston-cylinder assembly (see figure) contains 10 L of air at 20oC. The cylinder has an internal diameter of 20 cm. The piston is 2 cm thick and is made of steel of density ρ = 7830
Air in the accompanying piston-cylinder device is initially in equilibrium at 200oC. The mass of the hanging weight is 10 kg and the piston diameter is 10 cm. As air cools due to heat transfer to the
A horizontal piston-cylinder device contains air at 90 kPa while the outside pressure is 100 kPa. This is made possible by pulling the piston with a hanging weight through a string and pulley
An insulated, vertical piston-cylinder assembly (see figure) contains 50 L of steam at 105oC. The outside pressure is 101 kPa. The piston has a diameter of 20 cm and the combined mass of the piston
Steam is compressed from p1 = 100 kPa, Vol1 = 1 m3 to p2 = 200 kPa, Vol2 = 0.6 m3. The external force exerted on the piston is such that pressure increases linearly with a decrease in volume.
A gas in a piston-cylinder assembly is compressed (through a combination of external force on the piston and cooling) in such a manner that the pressure and volume are related by pVn = constant.
In the preceding problem the piston has a cross-sectional area of 0.05 m2. If the atmospheric pressure is 100 kPa and the weight of the piston and friction are negligible, plot how the external force
A piston-cylinder device contains 0.03 m3 of nitrogen at a pressure of 300 kPa. The atmospheric pressure is 100 kPa and the spring pressed against the piston has a spring constant of 256.7 kN/m. Heat
A 100 kg block of solid is moved upward by an external force F as shown in the accompanying figure. After a displacement of 10 cm, the upper surface of the block reaches a linear spring at its rest
In problem 0-4-3[BEZ], assume the energetic efficiency (work transfer to the elevator (desired) to the electrical work transfer (required) to the motor), η, of the system to be 80%, (a) Determine
Nitrogen in a horizontal piston-cylinder assembly expands from an initial volume of 0.10 m3 to a final volume of 0.5 m3 as the gas is heated for 5 minutes by an electrical resistance heater consuming
Water enters a system, operating at steady state, at 100 kPa, 25oC, and 10 m/s at a mass flow rate of 200 kg/s. It leaves the system at 15 m/s, 1 MPa, 25oC. If the density (ρ) of water is 1000
The rate of energy transfer due to flow work at a particular cross-section is 20 kW. If the volume flow rate is 0.2 m3/min, determine the pressure at that location.
Water enters a pump at 100 kPa with a mass flow rate of 20 kg/s and exits at 500 kPa with the same mass flow rate. If the density (ρ) of water is 1000 kg/m3, determine (a) the net rate of flow work
Water (ρ = 1000 kg/m3) flows steadily into a hydraulic turbine through an inlet with a mass flow rate of 500 kg/s. The conditions at the inlet are measured as 500 kPa and 25oC. (a) Determine the
(a) Determine the constant force necessary to accelerate a car of mass 1000 kg from 0 to 100 km/h in 6 seconds. (b) Also calculate the work done by the force. (c) Verify that the work done by the
A driver locks the brake of a car traveling at 140 km/h. Without anti-lock-brakes, the tires immediately start skidding. If the total mass of the car, including the driver is 1200 kg, determine (a)
A car delivers 200 hp to a winch used to raise a load of 1000 kg. Determine the maximum speed of lift.
A block of mass 100 kg is dragged on a horizontal surface with static and kinetic friction coefficients of 0.15 and 0.09 respectively. Determine (a) The pull force necessary to initiate motion. (b)
In the accompanying figure, determine (a) The work done by the force F acting at an angle of θ = 20o in moving the block of mass 10 kg by a distance of 3 m if μs = 0.5. (b) What is the sign of the
If a therm of heat costs $1.158 and a kWh of electricity costs $0.106, then prices of (a) Heat (b) Electricity on the basis of GJ.
In 2003, the US consumed (a) 20 MMbd of crude oil. (b) 21.9 tcf (trillion cubic feet) of natural gas. (c) 1 billion tons (short) of coal. The Btu equivalents are as follows: 1 bbl crude oil: 5.8
On Aug. 20, 2011, the prices for crude oil (heating value 43 MJ/kg) and natural gas were quoted as 82.26 USD/Bbl and 3.94 USD/MMBtu in the world market. Compare the prices on a comparable scale
The USA consumed about 21 MMbd (million barrels per day) of crude oil (density 0.82 kg/L, heating value 47 MJ/kg), 67% of which is utilized in the transportation sector. Determine how many barrels of
A power plant has an average annual load of 2000 MW (electrical). If the overall thermal efficiency is 38%, what is the annual cost of fuel for (a) Natural gas ($1.26/Therm) (b) No. 2 fuel oil
A gas trapped inside a piston-cylinder device receives 20 kJ of heat (Q) while it expands performing a boundary work (WB) of 5 kJ. At the same time 10 kJ of electrical work (Wel) is transferred into
A gas station sells gasoline and diesel at $2.00/gallon and $1.75/gallon respectively. If the following data are known about the two fuels, compare the prices on the basis of MJ of energy: heating
A rigid cylindrical tank stores 100 kg of a substance at 500 kPa and 500 K while the outside temperature is 300 K. A paddle wheel stirs the system transferring shaft work at a rate of 0.5 kW. At the
The nutrition label on a snack bar, which costs $1.00, reads - Serving size 42 g; Calories Per Serving 180. Determine (a) The heating value in MJ/kg. (b) Price in cents per MJ of heat release. (c) If
A popular soda can contains 0.355 kg of soda, which can be considered to be composed of 0.039 kg of sugar and the rest water. If the calorific value is written as 140 Calorie (bio). (a) Calculate the
Consider three options for heating a house. Electric resistance heating with electricity priced at $0.10/kWh, gas heating with gas priced at $1.10/Therm and oil (density 0.8 kg/L, heating value 46.5
In order to determine which is a cheaper fuel, a student collects the following data for gasoline and diesel respectively. Price per gallon: $2.90 vs. $3.10; Heating value: 44 MJ/kg vs. 43.2 MJ/kg;
During charging, a battery pack loses heat at a rate of 0.2 kW. The electric current flowing into the battery from a 220 V source is measured as 10 amp. Determine(a) Q.(b) Wel,(c) Wext. Include sign.
A gas trapped inside a piston-cylinder device receives 20 kJ of heat while it expands performing a boundary work of 5 kJ. At the same time 10 kJ of electrical work is transferred into the system.
A gas at 300 kPa is trapped inside a piston-cylinder device. It receives 20 kJ of heat while it expands performing a boundary work of 5 kJ. At the same time 10 kJ of electrical work is transferred
An iron block of 20 kg undergoes a process during which there is a heat loss from the block at 4 kJ/kg, an elevation increase of 50 m, and an increase in velocity from 10 m/s to 50 m/s. During the
A person turns on a 100-W fan before he leaves the warm room at 100 kPa, 30oC, hoping that the room will be cooler when he comes back after 5 hours. Heat transfer from the room to the surroundings
A fully charged battery supplies power to an electric car of mass 3000 kg. Determine the amount of energy depleted (in kJ) from the battery as the car accelerates from 0 to 140 km/h.
A photovoltaic array produces an average electric power output of 20 kW. The power is used to charge a storage battery. Heat transfer from the battery to the surroundings occurs at 1.5 kW. Determine
The heating value (maximum heat released as a fuel is burned with atmospheric air) of diesel is 43 MJ/kg. Determine the minimum fuel consumption necessary to accelerate a 20 ton (short ton) truck
In 2002, the US produced 3.88 trillion kWh of electricity. If coal (heating value 24.4 MJ/kg) accounted for 51% of the electricity production at an average thermal efficiency (electrical work
A car delivers its power to a winch, which is used to raise a load of 1000 kg at a vertical speed of 2 m/s. Determine (a) The work delivered by the engine to the winch in kW. (b) The rate (g/s) at
A car delivers 96.24 kW to a winch, which is used to raise a load of 1000 kg. (a) Determine the maximum velocity in m/s with which the load can be raised. (b) If the heating value of the fuel used is
A semi-truck of mass 25,000 lb (1 kg = 2.2 lb) enters a highway ramp at 10 mph (1 m/h = 0.447 m/s). It accelerates to 75 mph while merging with the highway at the end of the ramp at an elevation of
We are interested in the amount of gasoline consumed to accelerate a car of mass 5000 kg from 5 to 30 m/s (about 60 mph) on a freeway ramp. The ramp has a height of 15 m. Assuming the internal energy
A jumbo jet with a mass of 5 million kg requires a speed of 175 mph for take off. Assuming an overall efficiency of 20% (from heat release to kinetic energy of the aircraft), determine the amount of
A 0.1 kg projectile travelling with a velocity of 200 m/s (represented by State-1) hits a stationary block of solid (represented by State-2) of mass 1 kg and becomes embedded (combined system is
A semi-truck of mass 20,000 lb accelerates from 0 to 75 mph (1 mph = 0.447 m/s) in 10 seconds. (a) What is the change in kinetic energy of the truck in 10 seconds? (b) If PE and U of the truck can be
A gas trapped in a piston-cylinder device is subjected to the energy interactions shown in the accompanying figure for 30 seconds: the electric resistance heater draws 0.1 amp from a 100 V source,
Can you calculate the percent elongation of materials based only on the information given in Fig. 2.6? Explain.
The note at the bottom of Table 2.5 states that as temperature increases, C decreases and m increases. Explain why.
You are given the K and n values of two different materials. Is this information sufficient to determine which material is tougher? If not, what additional information do you need, and why?
Modify the curves in Fig. 2.7 to indicate the effects of temperature. Explain the reasons for your changes.
Using a specific example, show why the deformation rate, say in m/s, and the true strain rate are not the same.
It has been stated that the higher the value of m, the more diffuse the neck is, and likewise, the lower the value of m, the more localized the neck is. Explain the reason for this behavior.
Explain why materials with high m values, such as hot glass and silly putty, when stretched slowly, undergo large elongations before failure. Consider events taking place in the necked region of the
Assume that you are running four-point bending tests on a number of identical specimens of the same length and cross section, but with increasing distance between the upper points of loading. What
Would Eq. (2.10) hold true in the elastic range? Explain.
Why have different types of hardness tests been developed? How would you measure the hardness of a very large object?
Which hardness tests and scales would you use for very thin strips of material, such as aluminum foil? Why?
Explain if it is possible for the curves in Fig. 2.4 to reach 0% elongation as the gage length is increased further.
List and explain the factors that you would consider in selecting an appropriate hardness test and scale for a particular application.

Showing 16700 - 16800 of 18208

First
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
Last

Services

Sitemap
Fun
Definitions
Become Tutor
Study Help Categories
Recent Questions
Expert Questions

Company Info

Security
Copyrights
Privacy Policy
Terms & Conditions
SolutionInn Fee
Scholarship

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Campus Ambassador

Secure Payment

Download Our App

© 2024 SolutionInn. All Rights Reserved