Physics Help

[gnarrr]

Please help me. I can't figure it out

 

[flippintricker]

it's been a while man. Just figure out weight of the box thing at the end, then use torques to get force on the cable?

 

[gnarrr]

i already know the weight of the box is 9.8x85kg=833N but once i get that i have no idea where to go. i try to do something but i get the completely wrong answer.

 

[slevin_kelevra]

find the force on the bar where the cable attaches. The sum of forces in the y direction is equal to 0. So it should be the opposite of the force(torque) where the beam is attached to the cable

 

[spqr]

You should use torque equations to solve this. Torque is the length of the beam multiplied by force, multiplied by the sine of the angle the force makes with the moment arm. (6x833*sin75)
Then you need to figure out what force from the cable, will provide the necisary torque to keep things in equalibrium.
Summary: The sum of the torques and forces in equalibrium is zero. Find the torque from the mass, then use this to find what the tension is.

 

[gnarrr]

i think i got it. i get 1511.6N as an answer.

 

[B.G]

holy fuck my teach did that exact Q like a month ago

but i wasnt paying attention so i dont remeber

but use torques and remember torques only work when perpendicular to the board so itl be like mgcos(theta) or mgsin(theta) then just work it out around point p the atachment to the wall. then find the torque the wall needs to exert

 

[B.G]

cable*

 

[NESblowjob]

try 6/4 X cos 15 i think that might get you the answer let me know

 

[Billek]

Make sure to include the beam!

 

[Billek]

Nevermind!