AimMent

For Class 8, 9 & 10

Foundation - a strong base in Physics, Chemistry, Maths & Biology

Concept-first questions with clear model answers across all four subjects, aligned to NCERT. Start early, build the habit, and walk into your board exams, NEET and JEE already ahead.

Class 824Class 924Class 1036
SubjectAllPhysics 19Chemistry 19Biology 19Mathematics 27
ChapterAllAtoms and MoleculesForce and Laws of MotionGravitationHeron's FormulaImprovement in Food ResourcesIs Matter Around Us PureLinear Equations in Two VariablesMatter in Our SurroundingsMotionNatural ResourcesNumber SystemsPolynomialsSoundStatisticsStructure of the AtomSurface Areas and VolumesThe Fundamental Unit of LifeTissuesWork and Energy

Showing 2 questions for Class 9. Tap a card to reveal the answer.

PhysicsGravitationmedium

State the universal law of gravitation and write its formula.

Reveal answer ↓

What it is

Every mass attracts every other mass with a force that grows with mass and shrinks fast with distance.

Answer

The universal law of gravitation states that every body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres. The force F = G m1 m2 / r^2, where G is the universal gravitational constant.

F = G m1 m2 / r^2

  • •Force is proportional to m1 x m2
  • •Force is inversely proportional to r^2
  • •F = G m1 m2 / r^2
  • •G is the gravitational constant

Why learn this

It keeps the Moon orbiting, satellites up and explains your weight - the law that runs the universe.

💡 Memory trick

More mass = more pull; double the distance = one-quarter the pull (inverse SQUARE).

PhysicsGravitationmedium

State Archimedes' principle. Why does an iron nail sink but an iron ship float?

Reveal answer ↓

What it is

Any object in a fluid feels an upward buoyant force equal to the weight of fluid it displaces.

Answer

Archimedes' principle states that when a body is fully or partly immersed in a fluid, it experiences an upward buoyant force (upthrust) equal to the weight of the fluid it displaces. An iron nail sinks because it displaces only a little water, whose weight is less than the nail's weight. An iron ship is hollow and wide, so it displaces a large volume of water whose weight equals the ship's weight, and so it floats.

Buoyant force = weight of displaced fluid

  • •Upthrust = weight of fluid displaced
  • •Nail displaces little water -> sinks
  • •Hollow ship displaces lots of water -> floats

Why learn this

It's why ships float, balloons rise and you feel lighter in water - core to shipbuilding and submarines.

💡 Memory trick

Archimedes: upthrust = weight of fluid pushed aside. Float if you displace enough water.