Physics (9-1) - 0972 CIE

Energy, Work And Power Continued

Muhtasari

Work is how energy gets moved around, and power is how fast that happens. But the bigger story is where our energy comes from in the first place: fossil fuels, the wind, the tides, the Sun and the atomic nucleus. Each source has its own balance of benefits and costs.

In this lesson you will link work done to energy transferred with \(W=Fd\), survey the major energy resources and weigh up their advantages and disadvantages, and calculate the efficiency of an energy transfer. You will also see why almost all our energy traces back to the Sun.

Malengo

  1. Understand that mechanical or electrical work done is equal to the energy transferred
  2. Recall and use the equation for mechanical working W = Fd = ∆E
  3. Describe how useful energy may be obtained, or electrical power generated, from: (a) chemical energy stored in fossil fuels (b) chemical energy stored in biofuels (c) water, including the energy stored in waves, in tides and in water behind hydroelectric dams (d) geothermal resources (e) nuclear fuel (f) light from the Sun to generate electrical power (solar cells) (g) infrared and other electromagnetic waves from the Sun to heat water (solar panels) and be the source of wind energy including references to a boiler, turbine and generator where they are used
  4. Describe advantages and disadvantages of each method in terms of renewability, availability, reliability, scale and environmental impact
  5. Understand, qualitatively, the concept of efficiency of energy transfer
  6. [Supplement] Know that radiation from the Sun is the main source of energy for all our energy resources except geothermal, nuclear and tidal
  7. [Supplement] Know that energy is released by nuclear fusion in the Sun
  8. [Supplement] Know that research is being carried out to investigate how energy released by nuclear fusion can be used to produce electrical energy on a large scale
  9. [Supplement] Define efficiency as: (a) (useful energy output) (%) efficiency = (× 100%) (total energy input) (b) (useful power output) (%) efficiency = (× 100%) (total power input) recall and use these equations

Maelezo ya Somo

Every machine, power station and living body runs on energy transfers, and none of them is perfect: some energy always spreads out uselessly. Knowing how to calculate work and efficiency, and how to judge an energy resource, is at the heart of the biggest decisions society faces about power and the climate.

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Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.

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Tathmini ya Somo

Hongera kwa kukamilisha somo la Energy, Work And Power Continued. Sasa kwa kuwa umechunguza dhana na mawazo muhimu, ni wakati wa kuweka ujuzi wako kwa mtihani. Sehemu hii inatoa mazoezi mbalimbali maswali yaliyoundwa ili kuimarisha uelewaji wako na kukusaidia kupima ufahamu wako wa nyenzo.

Utakutana na mchanganyiko wa aina mbalimbali za maswali, ikiwemo maswali ya kuchagua jibu sahihi, maswali ya majibu mafupi, na maswali ya insha. Kila swali limebuniwa kwa umakini ili kupima vipengele tofauti vya maarifa yako na ujuzi wa kufikiri kwa makini.

Tumia sehemu hii ya tathmini kama fursa ya kuimarisha uelewa wako wa mada na kubaini maeneo yoyote ambapo unaweza kuhitaji kusoma zaidi. Usikatishwe tamaa na changamoto zozote utakazokutana nazo; badala yake, zitazame kama fursa za kukua na kuboresha.

  1. A force of 20 N moves an object 5 m in the direction of the force. The work done is: A. 4 J B. 25 J C. 100 J D. 200 J Answer: C
  2. A machine takes in 800 J and gives 600 J of useful output. Its efficiency is: A. 25% B. 75% C. 133% D. 200 J Answer: B
  3. Which energy resource is NOT ultimately driven by the Sun? A. wind B. waves C. geothermal D. biofuel Answer: C
  4. The Sun releases its energy mainly by: A. burning hydrogen as a fuel B. nuclear fusion C. nuclear fission D. chemical reactions Answer: B
  5. Which is a renewable energy resource? A. coal B. natural gas C. nuclear fuel D. tidal Answer: D

Inapatikana kwenye programu ya Green Bridge

Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.

Maelezo kamili ya masomo yenye michoro
Msaidizi wa kujifunza wa AI
Soma bila mtandao, wakati wowote, mahali popote
Inapatikana kwa Android, Windows, macOS, na Linux

Inapatikana kwenye programu ya Green Bridge

Pakua programu ya Green Bridge CBT kwenye simu yako au kompyuta yako ili kupata maelezo kamili ya masomo, maswali ya mazoezi, na mengi zaidi.

Maelezo kamili ya masomo yenye michoro
Msaidizi wa kujifunza wa AI
Soma bila mtandao, wakati wowote, mahali popote
Inapatikana kwa Android, Windows, macOS, na Linux

Fanya Mazoezi ya Maswali ya Majaribio

Ungependa kufanya mazoezi ya maswali ya majaribio kuhusu Energy, Work And Power Continued? Pakua programu ya Green Bridge CBT ili kupata maswali ya majaribio na tathmini kamili za mazoezi kuhusu mada hii.

Pakua Programu Kwenye Google Playstore

Kila kitu unachohitaji ili kufaulu katika JAMB, WAEC & NECO.

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