Final answer:
It is true that merchandise must stay 18 inches from sprinklers for them to work effectively. High-voltage wires are not wrapped in insulating material; air insulates them. Lightning can travel through trees to reach Earth, even though wood is typically an insulator.
Step-by-step explanation:
The statement that merchandise must remain at least 18 inches from sprinklers to work properly is true. In regards to fire safety and prevention, keeping merchandise a certain distance away from sprinkler heads ensures that in the event of a fire, the sprinklers can operate effectively and distribute water to extinguish the flames without obstruction.
16. True or False - High-Voltage Wires Insulation
The statement that the high-voltage wires are held aloft by insulating connectors and wrapped in an insulating material is false. High-voltage wires connected to tall metal-frame towers are not generally wrapped in insulating material because the air around them acts as an insulator, and therefore the cost of adding additional insulation is not justified for the intended purpose.
14.6 Bernoulli's Equation
Squirting water from a garden hose a greater distance by partially covering the opening with your thumb is due to Bernoulli's principle. By covering the opening, you reduce the area through which the water can escape, which in turn increases the velocity of the water escaping. This is an application of Bernoulli's equation, which states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy.
79. True or False - Lightning and Wood Insulation
The statement that although wood is an insulator, lightning can travel through a tree to reach Earth is true. Wood is normally an insulator, but the immense electrical pressure from a lightning strike can force a current through it, particularly when the wood is wet, which reduces its resistive properties and allows the electricity to pass through more easily.