Question 18 In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.
Class 9 - Science - Work and Energy Page 159
Anonymous:
The diagrams are not there
Ok, I got them in my cousin's book.I can answer now
Answers
Answered by
268
Case-1
Here,the direction of the force acting on the block is perpendicular to the displacement.So, the work done by the force is 0.
Case-2
Here,the direction of the force acting on the block is in the direction of the displacement.So, the work done by the force will be positive.
Case-3
Here,the direction of the force acting on the block is opposite to the direction of the displacement.So, the work done by the force will be negative.
Here,the direction of the force acting on the block is perpendicular to the displacement.So, the work done by the force is 0.
Case-2
Here,the direction of the force acting on the block is in the direction of the displacement.So, the work done by the force will be positive.
Case-3
Here,the direction of the force acting on the block is opposite to the direction of the displacement.So, the work done by the force will be negative.
Answered by
121
In case (a) the force F is perpendicular to the displacement, hence work done =0.
In case (b),the force F is in same direction as that of displacement, hence work done is positive.
In case (c) , the force F is in opposite to the direction of displacement,hence work done is negative.
In case (b),the force F is in same direction as that of displacement, hence work done is positive.
In case (c) , the force F is in opposite to the direction of displacement,hence work done is negative.
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