The answer will depend on what material the sidewalk is made from and the maximum range in temperature.
81 Square feet.
A 2-foot border around a 20 x 14 area makes the area 24 x 18 making the perimeter 84 feet.
10 miles = 52,800 feet, thus there are 52,800 x 15 = 792,000 ft2 of sidewalk (or pavement)
If there's a two foot border around a 14 x 20 foot area, that makes it 18 x 24 feet, with a perimeter of 84 feet.
10 feet and 8 feet to provide clearace for the tool joints
10 feet.
they r called contraction joints. then every few of those then expansion joint. concrete is going to crack, so make it crack so it can't be seen,under the man made ones. concrete tends to crack symmetrically. so if ur sidewalk is 3 feet wide the contraction joints will be every 3 feet. then expansion joint, 3/4 inch with expansive material, every 4th one.
Expansion joints are used on long runs (over 100 feet) of pipe or ducts where the expansion of steel will create stress on the pipe or its supports. for every 1 degree change in metal temperature the pipe will expand 6 millionths of a foot per foot of length. on a steam pipe 400 foot long carrying 750 degree steam this expansion would amount to a change in length of the pipe of 1.632 feet. this could tear down the supporting structure if this expansion weren't relieved by an expansion joint every 100 feet. expansion joints could be flexible corrugated pipe, reinforced rubber sheet, sliding pipe joints, or expansion loops, among other things.
Expansion joints are used in various types of structures and systems to accommodate the movement caused by thermal expansion, contraction, vibrations, settlement, or other dynamic forces. They are designed to prevent damage to the structure by allowing controlled movement while maintaining the structural integrity. Here are some common applications where expansion joints are used: **Buildings and Structures**: **Buildings**: Expansion joints are used in buildings to accommodate the movement caused by temperature changes and structural settling. They are often found in floors, walls, ceilings, and facades. **Bridges**: Expansion joints are critical in bridges to allow for the movement of the bridge components due to temperature fluctuations, traffic loads, and seismic activity. **Roads and Highways**: Expansion joints are used in roadways and highways to prevent cracking and damage due to thermal expansion and contraction. They also accommodate the movement caused by heavy traffic loads. **Piping Systems**: **Industrial Pipelines**: Expansion joints are installed in piping systems to absorb thermal expansion and contraction of pipes caused by temperature changes in the fluid being transported. **HVAC Systems**: In heating, ventilation, and air conditioning systems, expansion joints help compensate for the expansion and contraction of ductwork due to temperature changes. **Railways and Transit Systems**: **Railway Tracks**: Expansion joints are used in railway tracks to allow the rails to expand and contract with temperature changes. This helps prevent buckling and warping of the tracks. **Subway and Light Rail Systems**: Expansion joints are used in tunnels and station structures to accommodate the movement caused by ground settlement and vibrations. **Water and Wastewater Systems**: **Water Treatment Plants**: Expansion joints are used in water and wastewater treatment facilities to handle the movement of pipes and structures due to changes in water pressure, temperature, and ground settlement. **Aerospace and Transportation**: **Aircraft**: Expansion joints are used in aircraft components to accommodate the movement caused by changes in air pressure and temperature during flight. **Automobiles**: Expansion joints are found in exhaust systems and other components to absorb vibrations and thermal expansion. **Industrial Facilities**: **Manufacturing Plants**: Expansion joints are used in industrial facilities to allow for the movement of equipment, machinery, and structures due to temperature changes and vibrations. **Power Plants**: Expansion joints are used in power plants to handle the movement of pipes, boilers, and other components caused by temperature changes and pressure differentials. **Marine Structures**: **Harbors and Ports**: Expansion joints are used in dock structures and seawalls to accommodate tidal fluctuations and other dynamic forces. **Shipbuilding**: Expansion joints are used in shipbuilding to accommodate movement in the hull and other components. These are just a few examples of the many applications of expansion joints. The specific type of expansion joint used will depend on the requirements of the structure or system, the type of movement expected, and other factors. Proper design, installation, and maintenance of expansion joints are essential to ensure the longevity and functionality of the structure or system.
Impossible to answer - without knowing the depth of the sidewalk !
As you walk barefoot on a hot sidewalk, the sidewalk molecules vibrate more due to the heat, transferring thermal energy to your feet. The heat is moving from the sidewalk (higher temperature) to your feet (lower temperature), causing your feet to feel hot. The increased molecular vibrations in the sidewalk result in the sensation of heat on your feet as thermal energy is transferred.
84
152/(6*6) = 4.22... (recurring) feet.
The person's feet push backward on the sidewalk; the sidewalk pushes forward on the person.
conduction
To calculate the volume of concrete needed for the sidewalk, first convert the 4 inches thickness to feet (4 inches = 1/3 feet). Then, multiply the length (40 ft) by the width (3 ft) by the thickness in feet (1/3 ft) to get the total volume in cubic feet. This comes out to be 40 ft * 3 ft * 1/3 ft = 40 cubic feet of concrete needed for the sidewalk.
These gaps are thermal expansion joints, they prevent the rails from buckling when they get hot in the summer. Although modern welded rail only has these gaps every mile or so to reduce the vibration and noise of the wheel crossing them (instead of every 40 feet on unwelded rail). All construction must provide for thermal expansion (e.g. bridges have thermal expansion joints, concrete road paving has thermal expansion grooves).