Explanation

Terrestrial planets are rocky planets, including Earth, Mars, Venus, and Mercury.

These planets have solid, rocky surfaces.

Unlike gas giants which are composed mainly of gases.

Explanation

A magnifying glass uses a convex lens to enlarge the appearance of objects.

Convex lenses converge light rays to a focal point, producing a magnified image.

Explanation

Gravitational force (F) is given by:

F ∝ (m1 * m2) / r²

If both masses (m1 and m2) are halved:

New force F' ∝ ((m1/2) * (m2/2)) / r²

F' ∝ (m1 * m2) / (4 * r²)

F' = F / 4

The gravitational force becomes one fourth.

Explanation

Work done (W) is calculated as:

W = F * d * cos(θ)

where F is the force, d is the displacement, and θ is the angle between the force and displacement.

For work done to be zero, cos(θ) needs to be 0, which happens when:

θ = 90°

Explanation

Eduard Zirm performed the world's first successful human cornea transplant in 1905.

The operation restored vision to a man who had been blinded by a chemical burn.

Explanation

The Earth moves in two primary motions: Rotation (spinning on its axis) and Revolution (orbiting around the Sun).

Rotation causes day and night, while revolution leads to seasons.

Explanation

Celestial bodies that do not have their own heat and light are known as planets. Planets are lit by the light of stars, such as our sun.

Stars: Celestial bodies that emit their own light.

Asteroids: Tiny bodies that move around the sun, found between the orbits of Mars and Jupiter.

Comets: Bodies in space that are seen by reflected light.

Explanation

21 March and 23sept equal day and night.

The whole earth experiences equal days and equal nights is called an equinox

In Nairobi (Libya) equal day and night happen.

The shortest day occurs in the Northern Hemisphere is on the 22nd of December

The longest day occurs in the Northern Hemisphere is on 22nd June

Explanation

Momentum is the product of an object’s mass and its velocity → Momentum = Mass × Velocity.

It is a vector quantity.

It is conserved in closed systems during collisions.

Explanation

 Wind speeds of 10–13 kilometers per hour (kph) are considered light breezes.

At this speed, wind may rustle leaves, move small branches, or flutter light flags, but it does not cause damage.