# PhysicsA 10 Kg block lies on a smooth plane inclned at 51 degrees. What force parallel to the incline

#### JessiMen

##### New member
A 10 Kg block lies on a smooth plane inclined at 51 degrees. What force parallel to the incline would prevent the block from slipping?

#### MarkFL

Staff member
Can you post your progress so far, so our helpers can see how best to help?

#### JessiMen

##### New member
oh I skipped this question in my review because i didnt know how to do it there is also a question b to it:

b) An object is dragged 6 m up a ramp under a constant force of 27 N applied at an angle of 32 degrees to the ramp. Calculate the work done

#### topsquark

##### Well-known member
MHB Math Helper
oh I skipped this question in my review because i didnt know how to do it there is also a question b to it:

b) An object is dragged 6 m up a ramp under a constant force of 27 N applied at an angle of 32 degrees to the ramp. Calculate the work done
...And what have you been able to do so far?

-Dan

#### JessiMen

##### New member
for this question nothing because i have no idea how to start it.

#### MarkFL

Staff member
for this question nothing because i have no idea how to start it.
Okay, let's begin with a great tool used in physics called the free body diagram:

Okay, we wish to find the magnitude of the force $F$, which is equal in magnitude to $F_x$. We know the magnitude of $w$ (the weight vector) and we know $\theta$ where $\theta+\beta=\dfrac{\pi}{2}$...so can you use some trigonometry to relate $w$, $F_x$ and $\theta$?

#### Evgeny.Makarov

##### Well-known member
MHB Math Scholar
It seems to me that the figure would be clearer if $F_x$ and $F_y$ are renamed into $w_x$ and $w_y$ (and $w_x$ changes the direction). As I understand, $\vec{w}=\vec{w}_x+\vec{w}_y$. The component $\vec{w}_y$ of $\vec{w}$ is counterbalanced by the normal force $\vec{n}$ and $\vec{w}_x$ is counterbalanced by $\vec{F}$. But $\vec{F}$ does not have a $y$ component.