Solving Physics Problems: Tension, Time & Mass

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Homework Help Overview

The discussion revolves around physics problems involving tension in ropes, acceleration, and the motion of masses connected by pulleys. The specific scenarios include a bucket being accelerated upwards, a two-mass pulley system, and a painting being hung at an angle.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the calculation of tension in the rope for an upward-accelerating bucket and question the correctness of their answers. They also explore the dynamics of a two-mass system and how to apply classical mechanics equations to determine the time until the heavier mass strikes the ground.

Discussion Status

Some participants have provided guidance on how to approach the problems, suggesting that relevant equations should be shown and that each question should be posted separately for clarity. There is acknowledgment of correct calculations, but also a request for more detailed attempts at solutions.

Contextual Notes

Participants are encouraged to follow forum rules by showing their work and relevant equations. There is an emphasis on treating the problems as differences in masses and applying classical mechanics principles.

Alpha2
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1. A bucket of mass 4.03 kg is pulled by a rope and accelerated straight upwards at a rate of 1.62 m/s2. What is the tension in the rope? Express your answer in Newtons.

2. Two masses are connected by a light string and pulley as shown below. The mass on the left is 2.34 kg and the mass on the right is 3.60 kg. The system is released from rest. If the heavier mass starts at a height of 1.51 m above the ground, at what time will it strike the ground? Express your answer in seconds.

3. A boy purchases a copy of the Mona Lisa and hangs it from two ropes as shown below. The angle, is 27.8 degrees. If the Mona Lisa's mass (including the frame) is 4.56 kg, what is the tension in each rope? Express your answer in Newtons.



~For the first one I got 46.02260000000001 Newtons... but I don't know. =/
 
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I know they're most likely 'easy,' but I am really bad at this. I'm just really looking for someone to guide me through them I guess.
 
Alpha2 said:
1. A bucket of mass 4.03 kg is pulled by a rope and accelerated straight upwards at a rate of 1.62 m/s2. What is the tension in the rope? Express your answer in Newtons.

2. Two masses are connected by a light string and pulley as shown below. The mass on the left is 2.34 kg and the mass on the right is 3.60 kg. The system is released from rest. If the heavier mass starts at a height of 1.51 m above the ground, at what time will it strike the ground? Express your answer in seconds.

3. A boy purchases a copy of the Mona Lisa and hangs it from two ropes as shown below. The angle, is 27.8 degrees. If the Mona Lisa's mass (including the frame) is 4.56 kg, what is the tension in each rope? Express your answer in Newtons.



~For the first one I got 46.02260000000001 Newtons... but I don't know. =/
Hi, Alpha2, welcome to PF, your first answer is correct (but get rid of all those extra numbers after the decimal point!), so you're doing something right :smile:, but please show your relevant equations and attempt at a solution for the next two, per forum rules , following the format listed when you post. Also, please post each question separately, showing what equations you think apply and how you might solve the problem. Also, a picture or sketch would help. Thanks.
 
For the second one, treat these types of problems as differences in masses. So having a 3kg mass on one side, and having a 2kg mass on the other side, is exactly the same as having a 1kg mass(3-2) on one side and nothing on the other.

So all you have to do is use your formula for classical mechanics which is d = x + vt + (at^2)/2. since your initial velocity and initial distance are both 0, you are going to have 1.51 x 2 = at^2. Once you find a, which shouldn't be hard, just solve for t.
 
and by distance i mean initial distance which i denoted using 'x'.
 

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