Energi Terbarukan (Fisika SMA kelas 10 Kurikulum Merdeka)

Water Wheel Mechanics and Energy Concepts
📌 Farmers in Manggungsari Village, Tasikmalaya, have used a 5-meter diameter water wheel for 60 years to irrigate rice fields during the dry season using water from the Cintandui river.
🌊 The calculation for water flow rate (Discharge, $Q$) is defined as $Q = V/t$, where $V$ is volume ($m^3$) and $t$ is time ($s$).
⚙️ The flow of water exerts a thrust force that creates a torque ($\tau = F \cdot r$) on the water wheel, causing it to rotate and lift water to a height of 5 meters.
⚖️ Work ($W$) done by the thrust force is mathematically expressed as $W = F \cdot \Delta s$, and Power ($P$) is defined as $P = W/t$.

Types of Energy and Conservation Laws
kinetic energy ($E_k$) is calculated as $E_k = \frac{1}{2}mv^2$, where $m$ is mass (kg) and $v$ is velocity ($m/s$).
⚛️ Gravitational Potential Energy ($E_p$) is formulated as $E_p = mgh$, where $g$ is gravitational acceleration ($\approx 10\ m/s^2$) and $h$ is height ($m$).
🔥 Heat (Calor, $Q$) transfer is defined by $Q = mc\Delta t$, with $c$ being specific heat capacity ($J/kg\cdot K$) and $\Delta t$ the change in temperature.
⚡ Electrical energy ($W$) can be calculated using $W = VIt$ or $W = I^2Rt$, where $V$ is voltage ($V$), $I$ is current ($A$), $R$ is resistance ($\Omega$), and $t$ is time ($s$).

Energy Conservation and Conversion
🔄 The Law of Conservation of Energy states that energy cannot be created or destroyed, only transformed, demonstrated by a falling coconut converting potential energy to kinetic energy ($E_{mechanical} = E_k + E_p$).
💡 Examples of energy conversion include electrical energy transforming into sound (e.g., in a doorbell) or electrical energy turning into light (e.g., in a neon lamp).
🔄 Other conversions include electrical to heat (e.g., electric stove) and electrical to motion (e.g., fan, washing machine).

Energy Urgency and Sources
📈 Indonesia faces an increasing electricity consumption rate and an energy crisis, heavily relying on imports, which strains the national budget.
♻️ Renewable energy sources include solar, hydro, wind, ocean waves, tides, bioenergy, and geothermal energy, offering advantages like being inexhaustible and environmentally friendly.
❌ Non-renewable sources such as coal, petroleum, and natural gas are finite, commonly used, but have significant drawbacks like pollution and environmental degradation.
🌍 Global efforts are focused on achieving SDG 7 (Affordable and Clean Energy) by 2030 to ensure sustainable energy availability for all societies.

Key Points & Insights
➡️ The water wheel, though simple, demonstrates fundamental physics principles like thrust, torque, work, and power in real-world irrigation systems.
➡️ Energy is crucial for modern society, highlighting the urgency to transition from finite, polluting sources to sustainable alternatives.
➡️ Renewable energy deployment faces challenges like dependency on natural conditions (weather/tides) and the need for advanced conversion technology (e.g., solar panels).
➡️ SDG 7 provides a framework emphasizing clean energy, aiming to reduce global warming effects and foster economic opportunity through sustainable energy use.

📸 Video summarized with SummaryTube.com on Jan 22, 2026, 22:36 UTC