Grade 4 Science And Technology Force and Energy – Energy Notes
Science & Technology — Force and Energy
Subtopic: Energy (Nishati)
Energy (Nishati) is what things need to move, to heat, to light, and to work. Without energy, nothing would happen.
Simple definition
Energy is the ability to do work. Work can be moving things, making heat, or making light.
Everyday examples
- Sun heating the ground (Jua)
- Food giving energy to children (Chakula)
- Battery powering a torch (Betri)
- Car moving on the road (Gari)
Types of energy (Aina za nishati)
⚡
Electrical
Light bulbs, TVs
🔥
Heat (Thermal)
Cooking, warm hands
💪
Kinetic
Moving ball, running
🔋
Chemical
Food, petrol
🌞
Light
Sunlight, torch
🔊
Sound
Music, clap
How energy moves
Energy can change from one type to another. Examples:
- Sunlight (light) → Plant uses it to grow (chemical energy)
- Food (chemical) → You run (kinetic)
- Battery (chemical) → Torch gives light (electrical → light)
Energy is not lost
Energy cannot be made or destroyed. It only changes form. This is called conservation of energy. For example, when a car stops, its motion becomes heat.
Fun mini-activities (Do with an adult)
- Rolling ball: Push a ball on the ground. It has kinetic energy. Try pushing it harder — it goes faster.
- Rub hands: Rub your hands together quickly. You feel heat — motion changed to thermal energy.
- Rubber band: Stretch a rubber band and let it go. It snaps back — stored (potential) energy becomes kinetic.
Quick safety note:
Always do experiments with a grown-up. Do not play with fire or mains electricity.
Easy energy-saving tips (Kenya homes & schools)
- Turn off lights when not needed.
- Switch off chargers when phone is full.
- Dry clothes in the sun instead of using a dryer.
- Walk or use a bicycle for short trips when possible.
Mini diagram: ball on a slope (see energy change)
⚪
Top: more potential energy
Bottom: more kinetic energy
The ball at the top has stored (potential) energy. When it rolls down it gains kinetic energy and moves faster.
Quick quiz (write answers)
- What gives plants energy to grow?
- Name two types of energy.
- Give one way to save energy at home.
Key words (Maneno muhimu)
- Energy — Nishati
- Kinetic energy — Nishati ya mwendo
- Potential energy — Nishati iliyohifadhiwa
- Conservation — Uhifadhi (nishati haianguki)
Well done! Try the activities and ask your teacher or parent about other examples of energy around you.