The discussion revolves around calculating the torque exerted by a person standing on a ladder leaning against a house at a specific angle. The problem involves understanding the concepts of torque, forces, and angles in a physics context.
Several participants have provided calculations and interpretations regarding the torque's magnitude and direction. There is an ongoing exploration of the implications of different setups, such as the ladder's position relative to the house, and how that affects the torque's sign and direction. Guidance on using the right-hand rule has been shared, although some confusion remains.
Participants are navigating through the complexities of torque directionality and the conventions of positive and negative values in their calculations. There is mention of the physical setup and the need for consistent application of definitions and rules.
Start by drawing a sketch, showing the angle the ladder makes with the wall, then look up the definition of torque. What do you get?courtney1121 said:Imagine that a ladder leans against the house at an angle of 20o with respect to the vertical. A person with a weight of 650 N stands on the ladder at a point 1.0 m from its bottom. What are the magnitude and direction of the torque that this person exerts on the ladder around the point where the ladder touches the ground?
Where do I start?
Magnitude is correct, don't forget units!(joules).courtney1121 said:Is the direction towards me then? If I am looking at the house, the ladder is on the right of the house.
What are you afraid of straining your wrist? The direction is clockwise, but AWAY from you this time. You must get that thumb passing through the point about which the torque is taken. That negative sign indicates that the direction is opposite the direction in the first case when the ladder was on the other side. Usually clockwise moments are considered positive, and counter clockwise moments are negative, but it doesn't generally matter too much as long as you are consistent. Try it again, and strain your wrist and you'll get it!courtney1121 said:well, the torque will be the same but shouldn't it be negative so -222.3J and the direction would be towards me again but clockwise?
Ya, thanks a lot, now i need an Ace bandage.courtney1121 said:haha people are looking at me like I'm trying to hitch hike in my room...but i see now why it is pointing away from me.