Calculate Force on Small Gear from Torque with Pully and Shaft

AI Thread Summary
A pulley with a radius of 0.2 m exerts a torque of 0.002 Nm when a force of 0.01 N is applied. This torque is transferred to a small gear with a radius of 0.01 m. Using the same torque equation (T = Fr), the force on the small gear is calculated to be 0.2 N. The smaller radius of the gear results in a larger force needed to maintain the same torque. The calculations and method used are confirmed to be correct for similar problems.
Physics_wiz
Messages
227
Reaction score
0
A pully with radius .2 m is fixed on a shaft and on the other end there's a gear with radius .01 m. If a force of .01 N pulls down on the pully, what's the force on the tip of the small gear?

Here's my work:
The force produces a torque about the shaft T = Fr = (.01 N)(.2 m)= .002 Nm

The small gear is subjected to the same torque so T = Fr again,
.002 Nm = (F2) (.01 m)
F2 = .2 N

I know this is a simple problem, but I have to make sure I did it right because it's part of a bigger problem. So, did I do it right?
 
Physics news on Phys.org
Yeah, i think so
 


Yes, you have correctly calculated the force on the tip of the small gear. Your method of using the torque equation (T=Fr) to find the force is correct. Since the small gear has a smaller radius than the pulley, it will experience a larger force to produce the same torque. This is because torque is the product of force and distance, and since the distance (radius) is smaller for the small gear, the force must be larger to achieve the same torque. Overall, your calculation is correct and you can use this method for similar problems in the future.
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top