NCERT Class 9 Science Chapter 10 Work and Energy Solutions
NCERT Class 9 Science Chapter 10 Work and Energy Solutions GENERAL SCIENCE TEXTUAL QUESTIONS AND ANSWERS INTEX QUESTIONS AND ANSWERS 1. A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig.). Let us take it that the force acts on the object through the displacement. What is the work done in this case? Ans. Force, F = 7 N Displacement, s = 8 m ∴ Work done, W = Fs = 7 N × 8 m = 56 N m = 56 j. 1. When do we say that work is done? Ans: When do we say that work is done? Ans. Work is said to be done when force applied on an object shows the displacement in that object. W = F x s. 2. Write an expression for the work done when a force is acting on an object in the direction of its displacement. Ans. Work done = Force × Displacement, when the force is acting on the object in the direction of displacement. 3. Define 1 J of work. Ans. One joule (J) is the amount of work done on an object when a force of 1 N displaces it by 1 m along the distance line ...