JSS 2 Second Term Examination: Science Questions and Answers
Topic: Energy and Forces
- Chemical energy:
- Chemical energy is stored in the bonds of atoms and molecules and can be released during a chemical reaction.
- Example: When gasoline undergoes combustion in a car engine, chemical energy is converted into kinetic energy to power the vehicle. 🔥
- Kinetic energy:
- Kinetic energy is the energy of motion. It depends on the mass and velocity of an object.
- Example: A moving car has kinetic energy, which can be converted into other forms of energy such as sound energy when its brakes are applied. 🚗➡️🔊
- Gravitational pull:
- The closer an object is to the center of the Earth, the greater the gravitational pull it experiences.
- Example: A person standing on the surface of the Earth experiences a stronger gravitational pull compared to someone in space. 🌍➡️👩🚀
- Galaxies:
- A galaxy is a large group of stars, gas, and dust bound together by gravity.
- Example: The Milky Way is a galaxy that contains our solar system along with billions of other stars. 🌌
- Force:
- Force is the action that changes the position or shape of an object. It can be a push or a pull.
- Example: Pushing a door to open it or pulling a box across the floor both involve the application of force. 💪
- Natural satellite:
- A natural satellite is a celestial body that orbits around a planet.
- Example: The Moon is Earth’s natural satellite, orbiting around it as it revolves around the Sun. 🌕🌎
- Renewable vs. Non-renewable energy:
- Renewable energy sources can be replenished naturally and are sustainable, while non-renewable sources are finite and cannot be easily replaced.
- Example: Solar energy and wind energy are renewable sources, while fossil fuels like coal and oil are non-renewable. ☀️🌬️ vs. 🛢️🔥
- Energy conversion:
- Energy can be converted from one form to another. For example, electrical energy can be converted into sound energy in an electric doorbell.
- Example: When you press the button on an electric doorbell, electrical energy is converted into sound energy, producing a ringing sound. 🔔🔌➡️🔊
- Solar system:
- The sun and all the celestial bodies that orbit around it, including planets, moons, asteroids, and comets, make up the solar system.
- Example: The eight planets, including Earth, orbit around the Sun within our solar system. 🌞🌍🪐
- Heat transfer:
- Heat can be transferred from one point to another through various methods, including conduction, convection, and radiation.
- Example: When you place a metal spoon in a hot cup of tea, heat is transferred from the tea to the spoon through conduction. ☕️🥄🔥
- The primary source of energy is _____.
a) Chemical
b) Kinetic
c) Potential
d) Thermal - The closer an object is to the center of the Earth, the ____ the gravitational pull.
a) Stronger
b) Weaker
c) Same
d) No effect on - A galaxy is a large group of _____.
a) Planets
b) Stars
c) Comets
d) Moons - ____ is the action that changes the position and shape of a body.
a) Satellites
b) Force
c) Gravity
d) Weightlessness - A natural satellite is _____.
a) Man-made
b) Artificial
c) Made of metal
d) Not of the above - All are natural sources of energy except _____.
a) Sun
b) Electric generator
c) Water
d) Food - The energy conversion in an electric doorbell is from _____.
a) Electrical energy to sound energy
b) Sound energy to electrical energy
c) Electrical energy to heat energy
d) Heat energy to electrical energy - Which of the following is an artificial source of energy?
a) Generator plant
b) Water
c) Wind
d) Sun - The sun and all the planets make up the _____.
a) Solar system
b) Moon
c) Universe
d) Galaxy - The process by which heat is moved from one point to another point is called _____.
a) Convection
b) Conduction
c) Radiation
d) Sublimation - Non-contact force is also known as _____.
a) Field force
b) School force
c) Dynamic force
d) Solar force - Chemical energy can be found in all except _____.
a) Food
b) Peirol
c) Television
d) Batteries - ____ is not a method of heat transfer.
a) Bio gas
b) Heat transfer
c) Heat burning
d) Flames - The closer an object is to the center of the Earth, the ____ the gravitational pull.
a) Stronger
b) Weaker
c) Same
d) No effect on - A galaxy is a large group of _____.
a) Planets
b) Stars
c) Comets
d) Moons
- What is chemical energy?
- Chemical energy is stored in things like food and batteries.
- What does kinetic energy mean?
- Kinetic energy is the energy of movement, like when you kick a ball.
- Why does an object get pulled towards the Earth?
- The closer an object is to the Earth, the stronger its pull, called gravity.
- What is a galaxy?
- A galaxy is a big group of stars, like our Milky Way.
- What is force?
- Force is when you push or pull something to make it move.
- What is a natural satellite?
- A natural satellite is something that orbits a planet, like the Moon around Earth.
- Which things give us energy naturally?
- The Sun, water, and food are natural sources of energy.
- How does an electric doorbell work?
- It changes electrical energy into sound energy to make a ringing sound.
- Can you name an artificial source of energy?
- Yes, a generator plant is one example of an artificial energy source.
- What is the solar system made of?
- The Sun and all the planets together make up the solar system.
- How does heat move from one place to another?
- Heat can move through things like air, water, and even space through processes like conduction, convection, and radiation.
- What’s another name for non-contact force?
- Non-contact force is also called a field force.
- Where can we find chemical energy?
- Chemical energy can be found in things like food and batteries.
- What’s a method of heat transfer?
- Conduction, convection, and radiation are all ways heat moves from one place to another.
- Why do objects fall towards the Earth?
- Objects fall towards the Earth because of gravity, which pulls them down.