Finding torque to life object at a certain acceleration

AI Thread Summary
To determine the torque required to lift a 38 kg weight with an acceleration of 1.1 m/s² using a motor connected to a cylindrical drum, one must first calculate the tension in the rope using Newton's second law. The tension force is then multiplied by the radius of the drum (0.6 m) to find the torque. The original poster is struggling to arrive at the correct answer and is asked to share their calculations for further assistance. The discussion emphasizes the importance of showing work to receive effective help. Accurate calculations and understanding of the underlying physics principles are crucial for solving the problem.
bambam123
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Homework Statement



A motor is connected to a solid cylindrical drum with a diameter of 1.2 m and a mass of 51 kg. A massless rope is attached to the drum and tied at the other end to a 38 \rm kg weight, so the rope will wind onto the drum as it turns.

What torque must the motor apply if the weight is to be lifted with an acceleration of 1.1 m/s^2

Homework Equations


i have no idea how to do this problem. Could somebody give a me a step by step walkthrough

The Attempt at a Solution


i first did Newtons second law for teh mass hanging. i found the force of tension. then i took the force of tension and multiplied it by radius of drum and i got the torque. but i keep getting the wrong answere
 
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ignore the rm after the 38
 
Welcome to Physics Forums.

bambam123 said:

Homework Equations


i have no idea how to do this problem. Could somebody give a me a step by step walkthrough
Sorry, but that is not how we give help here.

The Attempt at a Solution


i first did Newtons second law for teh mass hanging. i found the force of tension. then i took the force of tension and multiplied it by radius of drum and i got the torque. but i keep getting the wrong answere
Show us what you got for the tension and torque, and please show how you got it. Then we can provide help.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
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Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
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