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Rank in order, from largest to smallest, the sizes of the friction forces `vec(f)_(a)` to `vec(f)_(c)` in these `5` different situation. The box and the floor are made of the same materials in all situations.
`(a)`
`(b)`
`(c)`
`(d)`
`(e)`

A

`f_(d)ltf_(b)=f_(c)=f_(c)gtf_(a)`

B

`f_(c)ltf_(b)=f_(d)=f_(c)gtf_(a)`

C

`f_(b)=f_(c)=f_(d)=f_(c)gtf_(a)`

D

`f_(b)gtf_(c)=f_(d)=f_(c)gtf_(a)`

Text Solution

Verified by Experts

The correct Answer is:
D
`f_(b)gtf_(c)gtf_(d)gtf_(e)gtf_(a)` Situations `c` ,`d` and `e` are all kinetic frIction, which does not depend on either velocity ot accerleration. Kinetic friction is smaller than the masimum static friction that is exerted in `b`, `f_(a)-0` because no friction is needed to keep the object at rest.
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