Explanation

• Sputnik 1 was launched by the Soviet Union on October 4, 1957.
• It from the Baikonur Cosmodrome in Kazakhstan, marking the beginning of the space age.
• The successful launch shocked the world and triggered the Space Race between the Soviet Union and the United States.

Last verified on 09-03-2026

Explanation

• Car brakes are typically hydraulic systems, not pneumatic systems.

The examples of pneumatic systems:

• Spray gun: uses compressed air to atomize and spray paint or other materials.
• Bicycle pump: uses compressed air to inflate tires.
• Vacuum cleaner: uses compressed air to create suction and lift dust and debris.

Last verified on 09-03-2026

Explanation

• The unit of pressure equal to 1 newton per square meter (N/m2) is called a Pascal (Pa).
• It is named after French mathematician and physicist Blaise Pascal.

Last verified on 09-03-2026

Explanation

• Pascal's Law states that the pressure applied to a fluid (liquid or gas) in a container is transmitted equally throughout the fluid and to the walls of the container, and that the pressure is the same in all directions at a given point in the fluid.
• This principle has numerous applications in engineering, physics, and everyday life.

Last verified on 09-03-2026

Explanation

• Reflex actions are rapid, automatic responses to stimuli that occur without the involvement of the brain.
• Instead, they are mediated by the spinal cord or peripheral nerves.

Last verified on 09-03-2026

Explanation

The structure of the brain is similar to the structure of a Walnut, with both having:

• A hard outer layer (cranium vs. shell)
• A wrinkled surface (brain's cerebral cortex vs. walnut's surface)
• A distinct left and right half (brain's hemispheres vs. walnut's halves)

Last verified on 09-03-2026

Explanation

• The nervous system is the body system that controls and coordinates the functions of all other organ systems.
• It allowing for integration and regulation of various bodily functions.
• It consists of the brain, spinal cord, nerves, and sensory organs.

Last verified on 09-03-2026

Explanation

• The incorrect statement is: States of matter does not change during chemical reactions.
• During chemical reactions, states of matter can change.
• For example, a solid may dissolve in a liquid, a liquid may vaporize, or a gas may condense into a liquid.

Last verified on 09-03-2026

Explanation

• The ozone layer acts as Earth’s natural sunscreen, protecting life from the sun’s harmful ultraviolet (UV) radiation.
• UV radiation can cause skin cancer, eye damage, and harm to plants and animals.

Additional information:

• Chemical Formula: O₃ (three oxygen atoms)
• Layer Location: Stratosphere, 15–40 km above Earth
• Function: Absorbs UV-B and UV-C rays from the Sun
• Depletion Causes: Air pollution, CFCs, industrial chemicals
• Protection Measures: Reduce CFC use, ozone-friendly products

Last verified on 09-03-2026

Explanation

• Melting of ice is a physical change, as it only involves a change in state (from solid to liquid) without a change in chemical composition.

The examples of chemical changes:

• Burning of fuel
• Explosion of firework
• Burning of wood
• Cooking of food (breakfast, lunch, dinner)
• Bursting of crackers
• Burning of wax
• Rusting of iron
• Heating sulphur with iron fillings (to produce iron sulphide)
• Digestion of food
• Respiration in living things
• Photosynthesis in plants

Last verified on 09-03-026