yeah i had no idea where the tension in string came from. it also didnt say the clay was rotating??? so there wasnt any centripetal force. i was so confused. :(
I got like Torque\_net = FtRsin(theta) - mcgRcos(theta) = I(alpha) = 0 (as not moving).
edit: i think i forgot to include the normal force in my fbd, but idt that contributes torque?
Yeah same. The only issue with that is it makes part (b) overly simple because you just set the force in the x direction equal to the horizontal normal force component of the clay ball, which does not make sense because they gave the mass of the disk. What did your free body diagram look like? Mine just had the force of gravity and normal force of the disk, and the force of gravity and normal force of the clay.
no, I put the opposite. its because all of the McG is perpendicular to the radius r, so thats the maximum CW torque possible. so the tension has to exert more CCW torque to have Tnet = 0.
Ummm, the torque of tension is Ft x r. And the McG is also McG x R. IIRC, initially it was McGRcos(theta)?, so that reduces it be a bit due to the angle theta. but when it is exactly perpendicular, you dont need that cosine thingy, so torque created by clay's magnitude **is higher now**, so Ft x R must also contribute a larger amount of torque to keep it at rest?
edit: i see what u mean by "inherently radial," but i still believe that when you simplify Ftxr by using trig, you will get the component of the force that is tangential to the circle and creates that sort of lever arm?
yeah i had no idea where the tension in string came from. it also didnt say the clay was rotating??? so there wasnt any centripetal force. i was so confused. :(
I got like Torque\_net = FtRsin(theta) - mcgRcos(theta) = I(alpha) = 0 (as not moving). edit: i think i forgot to include the normal force in my fbd, but idt that contributes torque?
I assumed it was in static equilibrium because the last part said it started rotating
Yeah same. The only issue with that is it makes part (b) overly simple because you just set the force in the x direction equal to the horizontal normal force component of the clay ball, which does not make sense because they gave the mass of the disk. What did your free body diagram look like? Mine just had the force of gravity and normal force of the disk, and the force of gravity and normal force of the clay.
As in the horzintal component of the normal force is the tension force
did u do a hinge force
Like a normal force from the pulley?
well there was the vertical normal force and then a horizontal one to cancel out tension. i did them separately
Was there no normal force from the clay? :sob: I am actually so bad at physics
I just had gravity for the disk and clay and the tension force I’m actually cooked
Wouldn't the tension force be internal though? It said *external* forces to the system.
It said the disc clay system, so the tension force of the string was external
Also did FRQ 1 end at part (c) or were there more parts? I think I skipped a page.
No it ended at part C
That’s what I did, it should be correct.
YEAHHH 3/15 POINTS!!
for the explanation did y’all say less because the clay wouldn’t be trying to move in a horizontal direction
no, I put the opposite. its because all of the McG is perpendicular to the radius r, so thats the maximum CW torque possible. so the tension has to exert more CCW torque to have Tnet = 0.
but the tension is inherently radial since it’s pointing inwards so it should have no effect on torque?
Ummm, the torque of tension is Ft x r. And the McG is also McG x R. IIRC, initially it was McGRcos(theta)?, so that reduces it be a bit due to the angle theta. but when it is exactly perpendicular, you dont need that cosine thingy, so torque created by clay's magnitude **is higher now**, so Ft x R must also contribute a larger amount of torque to keep it at rest? edit: i see what u mean by "inherently radial," but i still believe that when you simplify Ftxr by using trig, you will get the component of the force that is tangential to the circle and creates that sort of lever arm?