Question

check your understanding (p. 149) #1 - 4
1 name two factors that reduce the efficiency of machines.
2 list three benefits of becoming more energy efficient.

Explanation:

Question 1:

To determine factors reducing machine efficiency, we consider physical principles. Friction occurs between moving parts, converting mechanical energy to heat, thus wasting energy. Air resistance acts on machines with moving components (e.g., vehicles, fans), opposing motion and requiring more energy to maintain operation, reducing efficiency.

Energy efficiency benefits are analyzed from economic, environmental, and resource perspectives. Cost savings come from reduced energy consumption (lower utility bills). Environmental benefits include less greenhouse gas emissions (mitigating climate change) as less energy production (e.g., from fossil fuels) is needed. Resource conservation means non - renewable energy sources (like coal, oil) are used less, preserving them for future generations.

Answer:

1. Friction (between machine parts)
2. Air resistance (for machines with moving parts exposed to air)

Question 2: