Maharashtra Board Class 9 Science — Flashcards for Quick Revision

A: Motion is the change in position of an object with respect to time and its surroundings. An object is said to be in motion if its position changes with respect to its surroundings. Example: A moving b

A: Distance is the total length of the actual path travelled by an object. Displacement is the minimum distance between the starting and finishing points (straight line distance). Distance is always posi

A: Speed is the distance travelled by an object in unit time. Formula: Speed = Total distance travelled / Time required. Unit: m/s (SI system) or cm/s (CGS system). Speed is a scalar quantity.

A: Work is said to be done when a force applied on an object causes displacement of the object. Formula: Work = Force × Displacement. Work is only done when there is movement in the direction of the appl

A: W = F × s × cos θ, where W is work, F is applied force, s is displacement, and θ is the angle between force and displacement directions.

A: SI unit: Joule (J) = 1 Newton × 1 metre. CGS unit: Erg = 1 dyne × 1 centimetre. Relationship: 1 Joule = 10⁷ erg

A: Electric potential is like an 'electric level' at a point. Just like water flows from higher level to lower level, positive charges flow from higher potential to lower potential. Electrons (negative c

A: Potential difference is the difference between the values of potentials at two points. It is the work done to carry a unit positive charge from one point to another. Formula: V = W/Q, where V = potent

A: Free electrons are the outermost electrons in metallic conductors that are weakly bound to the nucleus. They can easily move from one part of a conductor to another, carrying negative charge with them