Explanation

According to the positions of effort, fulcrum, and load, levers are divided into three kinds:

1. First kind of lever: The fulcrum is located between the effort and the load. Examples: See-saws, crowbars, hammer claws, scissors, pliers and boat oars.
2. Second kind of lever: The load is located between the effort and the fulcrum. Examples: Bottle opener, wheelbarrow, nut cracker, nail clippers, nail cutter, paper cutter and door.
3. Third kind of lever: The effort is located between the fulcrum and the load. Examples: Broom, tongs, human arm, stapler, fishing rod and tweezers.

Explanation

• The velocity of a wave (v) is equal to the product of its wavelength (λ) and frequency (f).
• This is expressed mathematically as: v = λf

Explanation

• Wood is an insulator and cannot conduct electricity.
• So it cannot be used to complete a circuit.

Explanation

• Friction is a force that opposes motion between two surfaces that are in contact.
• It acts in the opposite direction of motion, making it harder to move an object or keep it moving.

Explanation

In a gas, the particles are:

• Widely spread out, with no fixed position or arrangement
• Not in a regular pattern, with no repeating structure or order
• Separated by large empty spaces, with no close packing or cohesion

Explanation

• The correct answer is: Particles have large empty spaces between them.
• This statement is incorrect because particles in liquids have small spaces between them, not large empty spaces.

Explanation

• Asthma is a respiratory disease that can be triggered or exacerbated by exposure to air pollution.
• Air pollution can irritate the airways, trigger asthma attacks, and make symptoms worse.

Air pollution can cause:

• Respiratory problems: asthma, pneumonia, lung cancer
• Irritation: headaches, eyes and nose irritation, sore throat
• General symptoms: nausea, drowsiness, ill feeling
• Impaired judgment and weakened cognitive function

Explanation

• Frog eggs are known as Spawn.
• This term refers to the cluster of eggs laid by a female frog in water.

Explanation

• Escherichia coli (E. coli) is a type of bacterium.
• It is commonly found in the gut of humans and animals.
• It plays a important role in the digestive process. 

Explanation

• The Earth completes a day in a Solar day, which is approximately 24 hours.
• This is the time it takes the Earth to rotate once on its axis, causing day and night to cycle.