(a) Rubbing hands together |
(b) Scratching a match stick against the box |
(c) Sawing wood |
(d) Drilling a hole into metal sheet |
(e) Rubbing off some pencil marks with an eraser |
A) (a) and (e) only
B) (a), (b) and (e) only
C) (a), (b), (c) and (e) only
D) (a), (b), (c), (d) and (e)
Correct Answer: D
Solution :
As all these actions involve two surfaces rubbing against each other, thus force of friction comes into action which produces heat.You need to login to perform this action.
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