The correct answer is (c) Remains constant. When a body falls freely towards the Earth, its potential energy decreases while its kinetic energy increases. However, the total mechanical energy (sum of kinetic and potential energy) remains constant, assuming no air ...
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The correct answer is (a) the object gains energy. When mechanical work is done on an object, energy is transferred to it, increasing its kinetic or potential energy. This work-energy principle explains how forces acting on an object change its ...
In a tug of war, the winning team does positive work because they pull the rope in their direction, causing displacement. The losing team does negative work as they apply force but move in the opposite direction. Answer: (b) positive, ...
W = Force × Displacement × cosθ For work to be done, two conditions must be met: A force must act on the body. The body must be displaced in the direction of the force or a component of it.
When lifting the suitcase, the force applied is equal to its weight (mg) and the displacement is the height (h) of the table from the floor. Since the force and displacement are in the same direction(θ =0⁰), we get: Work ...
A and B experience the same buoyant force, the volume of water displaced by both must be equal. The volume of displaced water is equal to the volume of the submerged object. Thus, the volumes of metallic pieces A and ...
The smallest base area is breadth × width (800 cm²), meaning the maximum pressure is exerted in this case. Correct answer: (b) Maximum when breadth and width form the base. Class 9th Science NCERT MCQ Questions NCERT Books MCQ Questions ...
The atmosphere is held to the Earth by gravity (option a). Gravity keeps gases from escaping into space, maintaining the air we breathe. Without gravity, Earth’s atmosphere would dissipate, making life impossible. Class 9th Science NCERT MCQ Questions NCERT Books ...
The correct answer is (d) is independent of mass and radius of the Earth. The gravitational constant (G) is a universal constant with a fixed value 6.674 × 10−¹¹ N.M²/kg² It It remains the same everywhere in the universe and does ...
The correct answer is (a) P = F/A. Pressure (P) is defined as the force (F) applied per unit area (A). Mathematically, it is given by: P = F/A This means that pressure increases if force increases or area decreases.