Stem Summative Part 2

Explanation
A beam bridge is a type of bridge that is supported by a horizontal beam or multiple beams that are supported at each end by piers or abutments. This type of bridge is commonly used for short spans and is known for its simplicity and cost-effectiveness. The beams distribute the weight of the bridge and the load it carries evenly across the piers, making it a reliable and efficient design.

Explanation
An arch bridge is a type of bridge that is characterized by its curved shape. It is designed to distribute the weight of the bridge and the load it carries evenly along its curved structure. This design allows the bridge to span long distances without the need for additional support pillars or piers. Arch bridges have been used for centuries and are known for their strength, durability, and aesthetic appeal. They are commonly found in both modern and historical architecture.

Explanation
A cantilever bridge is a type of bridge that is supported on only one end, with the other end projecting out into space. It uses a cantilever structure, which is a rigid beam or structure that is anchored at only one end. The projecting section of the bridge is balanced by the weight on the anchored end, allowing it to support itself and any load placed on it. Cantilever bridges are commonly used for long spans where the use of piers or supports in the middle of the span is not possible or desirable.

Explanation
A cable-stayed bridge is a type of bridge where the deck is supported by cables that are attached to towers. The cables are arranged in a fan-like or harp-like pattern, providing support and stability to the bridge. This design allows for longer spans and fewer materials compared to other types of bridges. Cable-stayed bridges are known for their aesthetic appeal and are often used for medium to long spans.

Explanation
A suspension bridge is a type of bridge that is supported by cables from tall towers. The cables are attached to the ends of the bridge and are anchored into the ground. The main feature of a suspension bridge is the suspended roadway, which hangs from the cables. This type of bridge is known for its ability to span long distances and its elegant design. The weight of the bridge is distributed evenly along the cables, allowing for a stable and durable structure.

Explanation
A truss bridge is a type of bridge that is constructed using a framework of triangular units. The triangular units, or trusses, provide stability and support to the bridge structure. Truss bridges are known for their strength and ability to span long distances. They are commonly used in situations where a large amount of weight needs to be supported, such as highway overpasses or railroad bridges. Truss bridges are also relatively easy to construct and maintain, making them a popular choice for many bridge projects.

Explanation
Suspension bridges have main support cables that go from tower to tower. This is because the towers act as the main support structures for the bridge, holding up the weight of the roadway and distributing it to the ground. The cables are attached to the towers and hang down in a catenary curve, providing the necessary tension to support the bridge. By connecting the cables from tower to tower, the bridge is able to span long distances without the need for additional support structures in the middle.

Explanation
Cable-stayed bridges are supported by cables that extend from the towers to the roadway. These cables are responsible for bearing the load of the bridge and providing stability. The towers act as the main support structures, while the roadway is where vehicles and pedestrians travel. Therefore, the correct answer is "tower to roadway."

Explanation
Tension is a force that occurs when an object is being pulled from both sides. It is a result of opposing forces acting on an object, causing it to stretch or elongate. In this case, the correct answer is "pulled" because tension is commonly associated with the act of pulling an object in opposite directions.

Explanation
Compression is when an object is being pushed from both sides. This means that external forces are acting on the object, causing it to become compressed or squeezed. The object experiences a decrease in volume or thickness due to the applied pressure. In this case, the correct answer is "pushed" because it accurately describes the action of external forces pushing the object from both sides.

Explanation
Torsion refers to the twisting of an object, where it experiences a rotational force in opposite directions on both sides. This twisting action causes deformation in the object, leading to torsional stress. Therefore, the correct answer is "twisted."

Explanation
An actor cannot use the "next costume" block if they only have one costume because the "next costume" block is used to switch to the next costume in a sequence. If the actor only has one costume, there is no next costume to switch to, hence the block cannot be used.

Explanation
The statement "You can only use the 'play sound ______' block ONCE per project" is false. In a project, you can use the "play sound" block multiple times to play different sounds at different times or in response to different events. This allows for versatility in creating interactive and dynamic projects that involve playing various sounds.

Explanation
The statement "ONLY actors can use the 'play sound ____' block, not the stage" is false. Both actors and the stage can use the "play sound ____" block. This block allows them to play a specific sound during the execution of the program.

Explanation
The "when actor clicked" block can be used in the stage's code even though the stage itself is not an actor. This is because the stage is the main backdrop of the project and can still respond to events such as being clicked. The block allows for actions to be triggered when the stage is clicked, making it a valid option to use in the stage's code.

Explanation
The Brooklyn Bridge is the correct answer because it is well-known for its strength and durability. It was designed by John Augustus Roebling and completed in 1883. The bridge was a major engineering feat at the time and was considered one of the world's largest suspension bridges. To prove its strength, 21 elephants were led across the bridge in a procession. This demonstration showcased the bridge's ability to withstand heavy loads and solidified its reputation as a marvel of engineering.