Answer:
Step-by-step explanation:
To have rotational acceleration, the net torque must be nonzero. In order to solve for when the motion just begins, we will set net toque to zero
Torque = force * (distance from the pivot point) * sin Theta. All these force are 90 degrees from the lever arm making sin theta=1 so we will ignore that part for now.
Torque net= T load + T W + Tapp =0 Before we start plugging we must determine 2 things. Where is the pivot point and which torque is positve.
The pivot point is at x, because that is where the rod will rotate about when lifted at y.
Now standard notation had Counter clockwise as a positive and Clockwise as a negative. So lets look at each force individually to determine positive or negative. The load provides a force downward to the right of the pivot point which would cause a clockwise rotation therefore negative torque. The same thing is true for weight of the bar. The applied force has an upward force to the right of the pivot point which causes a counter clockwise rotation and therefore positive torque.
Now lets fix the equation with positives and negatives
- T load -T W + Tapp =0 Now we determine how far each force is away from the pivot point.
Load is 0.5 m
Weight is 2 m
and Fapp= 4 m
Now we plug in where torque = force * (distance from the pivot point)
- T load -T W + Tapp =0
- (120N)*(0.5m)-(W)(2m)+(65N)*(4)=0 simplifying gives us
-60-2w+260=0
200-2w=0
200=2w
w=100N
Hope this helps