Question Number 14923 by Tinkutara last updated on 05/Jun/17

A plane is inclined at an angle of 30°  with horizontal. Find the component  of a force F^→  = −10k^∧ N perpendicular to  the plane. Given that z-direction is  vertically upwards.

Answered by ajfour last updated on 10/Jun/17

F_⊥ ^� =(10cos 30°)(sin 30° i^� −cos 30° k^�  )N       = ((10(√3))/2)((1/2)i^� −((√3)/2) k^�  )N       = ((5(√3))/2)(i^� −(√3) k^�  )N .   ∣F_⊥ ^� ∣=5(√3) N .

Commented byTinkutara last updated on 10/Jun/17

Sir, wouldn′t it will be −5(√3)k^∧  N?

Commented byajfour last updated on 10/Jun/17

question is wrongly framed..  if force is ⊥ to incline plane , is   the force along z axis, how is   then the inclined plane oriented ?

Commented byTinkutara last updated on 10/Jun/17

Why kilo N? I was saying it would be  −5(√3) N or not? (minus sign)

Commented byajfour last updated on 10/Jun/17

if you mention the magnitude  it is 5(√3) N.(no minus sign)  while if the component of the  vertically downward force   perpendicular to the incline plane  to be written in vector form , then   F_⊥ ^� = 5(√3)((1/2)i^� −((√3)/2)k^� ).

Commented byTinkutara last updated on 11/Jun/17

Thanks Sir!