A body of mass m is slowly pulled up the hill by a force F which at each point was directed along the tangent of the trajectory as shown in figure. All surfaces are smooth. Find the work performed by this force.

Question

A body of mass m is slowly pulled up the hill by a force F which at each point was directed along the tangent of the trajectory as shown in figure. All surfaces are smooth. Find the work performed by this force. <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/6f63b35b262b74662b2bf5e5021d98f2-.png" /> (A) mgl (B) -mgl (C) mgh (D) Zero

Tardigrade Admin · Accepted Answer

Sigma W text net =Δ K As particle is moving slowly, this means Δ K=0 WN+WF+W mg =Δ K But WN=0 as vecN perp d vecr 0 +WF-m g h=0 WF=m g h

Q. A body of mass m is slowly pulled up the hill by a force $F$ which at each point was directed along the tangent of the trajectory as shown in figure. All surfaces are smooth. Find the work performed by this force.

mgl

-mgl

mgh

Zero

$Σ W_{net} = Δ K$
As particle is moving slowly, this means $Δ K = 0$
$W_{N} + W_{F} + W_{m g} = Δ K$
But $W_{N} = 0$ as $N ⊥ d r$
$0 + W_{F} - m g h = 0$
$W_{F} = m g h$

Q. A body of mass m is slowly pulled up the hill by a force F which at each point was directed along the tangent of the trajectory as shown in figure. All surfaces are smooth. Find the work performed by this force.

mgl

-mgl

mgh

Zero

ΣWnet ​=ΔK As particle is moving slowly, this means ΔK=0 WN​+WF​+Wmg​=ΔK But WN​=0 as N⊥dr 0+WF​−mgh=0 WF​=mgh

Q. A body of mass m is slowly pulled up the hill by a force $F$ which at each point was directed along the tangent of the trajectory as shown in figure. All surfaces are smooth. Find the work performed by this force.

$Σ W_{net} = Δ K$
As particle is moving slowly, this means $Δ K = 0$
$W_{N} + W_{F} + W_{m g} = Δ K$
But $W_{N} = 0$ as $N ⊥ d r$
$0 + W_{F} - m g h = 0$
$W_{F} = m g h$