38 topics · Preschool to Grade 8

How buildings and cities work

Where does tap water come from, and how does a skyscraper stand up in the wind? These topics explore the systems that keep a town running. Children follow clean water from the treatment plant to the faucet and wastewater back out again, time the traffic lights at a busy crossing, and see how bridges, tunnels, elevators and escalators are built and powered. They also discover the hidden helpers: fire sprinklers and hydrants, storm drains and flood barriers, canal locks, recycling centers and the people in an air traffic control tower. Every topic has an animated explanation, a part-by-part look inside, a hands-on simulation and a challenge, at three levels from preschool to middle school.

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38 topics in Buildings & city systems

Buildings & city systems

#59 Buildings & city systems How does clean water reach our taps? Follow water through treatment, storage, and underground pipes. Explore the removal of visible and microscopic contaminants, then connect a neighborhood's water supply.

#60 Buildings & city systems How do elevators work? Add passengers and watch the motor, cables, elevator car, and counterweight move together. Deliver people to different floors in a transparent building.

#61 Buildings & city systems What happens to water after it goes down the drain? Follow wastewater through sewers, screens, settling tanks, and biological treatment. Operate a model treatment plant and investigate each stage's purpose.

#62 Buildings & city systems How do bridges hold so much weight? Compare beam, arch, and suspension bridges. Add virtual traffic, watch simplified force arrows, and strengthen a bridge by changing its supports.

#63 Buildings & city systems How do skyscrapers stay standing? Explore foundations, columns, bracing, and structural cores. Build a model tower and compare how different designs respond to weight and wind.

#64 Buildings & city systems How do traffic lights manage busy roads? Program signals at an intersection and include pedestrian crossings. Compare how different timings affect queues and help everyone move through safely.

#65 Buildings & city systems How does a recycling center sort materials? Send materials along a conveyor and explore magnets, screens, and sorting equipment. Follow selected paper, metal, and plastic items into processing.

#66 Buildings & city systems How do construction cranes lift heavy things? Explore the boom, cables, pulleys, and counterweights. Move virtual loads while investigating how their position affects the crane's balance.

#67 Buildings & city systems How are tunnels built underground? Look inside a tunnel-boring machine and follow excavation, soil removal, and tunnel lining. Guide construction around underground obstacles in a model city.

#68 Buildings & city systems How are roads built? Build a layered model road, compact the surface, and add drainage. Explore how traffic, water, and temperature contribute to wear and potholes.

#158 Buildings & city systems How do door closers shut doors gently? Adjust spring tension and damping to control a model door's return.

#198 Buildings & city systems How do revolving doors help control airflow? Compare air movement through rotating compartments with an ordinary open doorway.

#199 Buildings & city systems How do automatic fire sprinklers release water? Warm a model sprinkler's heat-sensitive element and watch that individual sprinkler open.

#351 Buildings & city systems How do escalators move their steps? Look beneath the surface and follow linked steps circulating around the mechanism.

#352 Buildings & city systems How does airport luggage reach the correct plane? Scan baggage tags and guide bags through conveyors, sorting points, and loading areas.

#353 Buildings & city systems How do shipping ports move containers? Transfer containers between ships, storage yards, trains, and trucks.

#354 Buildings & city systems How do canal locks raise and lower boats? Operate gates and change chamber water levels to move boats between elevations.

#355 Buildings & city systems How do movable bridges let ships pass? Compare lifting, swinging, and tilting bridges while coordinating ships and road traffic.

#356 Buildings & city systems How do flood barriers protect towns? Place barriers and observe how rising water moves around protected areas.

#357 Buildings & city systems How do storm drains handle heavy rain? Follow street runoff and compare flooding when drains are clear or blocked.

#358 Buildings & city systems How do rain gardens reduce runoff? Arrange soil and plants and compare absorption with nearby paved surfaces.

#359 Buildings & city systems How do fire hydrants supply water? Look beneath a street and follow water through an opened hydrant.

#360 Buildings & city systems How do water towers maintain pressure? Change tank height and water level and observe pressure across a model neighborhood.

#361 Buildings & city systems How do desalination plants remove salt from seawater? Explore a simplified membrane system and compare its freshwater and concentrated saltwater outputs.

#362 Buildings & city systems How can one heating plant warm a neighborhood? Follow heat through insulated district pipes and building heat exchangers.

#363 Buildings & city systems How do prefabricated buildings fit together? Assemble factory-made sections and match their structural, plumbing, and electrical connections.

#364 Buildings & city systems How do retaining walls hold back soil? Compare wall shape, drainage, and reinforcement under different simulated loads.

#365 Buildings & city systems How do parking garages identify empty spaces? Move cars between bays and watch sensors update guidance signs.

#366 Buildings & city systems How do railway signals keep trains separated? Divide track into sections and operate signals as trains enter and leave.

#367 Buildings & city systems How does air traffic control organize flights? Guide aircraft along assigned routes and coordinate spacing and runway approaches.

#368 Buildings & city systems How do dry docks make ship repairs possible? Float in a vessel, close the gate, and lower water around its hull.

#369 Buildings & city systems How do utility maps show what is underground? Switch between pipe and cable layers before planning a simulated excavation.

#370 Buildings & city systems How does a stadium open and close its roof? Coordinate movable roof sections as they travel along their tracks.

#371 Buildings & city systems How do buildings use emergency backup power? Simulate an interruption and watch essential equipment transfer to a backup supply.

#372 Buildings & city systems How do roofs keep rain out? Layer materials, add flashing and drainage, and trace raindrops around joints.

#373 Buildings & city systems How can underground pipes be repaired without digging up a street? Insert a virtual lining and watch a repaired passage form inside a damaged pipe.

#374 Buildings & city systems How do utilities find hidden water leaks? Compare flow readings across a network and narrow down where water escapes.

#375 Buildings & city systems How do airport passenger bridges connect to airplanes? Adjust height, direction, and extension to meet different aircraft doors.

Keep exploring

Games to play

Bridge LabBuild a bridge from beams, brace it with triangles, and stay on budget.
Area ArchitectDesign rooms that hit the area and perimeter on the blueprint.
Route PlannerFind the shortest way around town, dodge closed roads, and measure trips with a scale bar.

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