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
Messages
2
Reaction score
0

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
 
Last edited:
Physics news on Phys.org
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.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top