# Tension downward acceleration problems

• dkgojackets
In summary: TL is the tension in the upper left string and TR is the tension in the lower right string. When the masses are attached to the pulley, the tension in the strings goes up by 1kg*g.
dkgojackets

Im supposed to find T1 and T2 using m1, m2, and g. The whole system is accelerating downwards with magnitude g/2.

Maybe if I get this I can figure out the more complex ones. Thanks.

dkgojackets said:

Im supposed to find T1 and T2 using m1, m2, and g. The whole system is accelerating downwards with magnitude g/2.

Maybe if I get this I can figure out the more complex ones. Thanks.
Draw free body diagrams for both the masses and see if you can work it out. We will help you if you show us your attempt.

Its tough to put in paint, but for m1 I have T1 going up, T2 going down, and .5(m1)g going down. On m2 I have T2 up and .5(m2)g down.

Looking at m2, I have the sum of forces being T2 - .5(m2)g

I'm not used to having the system accelerate, but right now I can only think of making T2 = .5(m2)g. T1 would be .5(m1 + m2)g then. I just don't think that is correct.

Nevermind, it is :)

OK here's the one I am really stuck on. I am just not completely sure what's going on. I'm looking for T. The units are kg for mass of the blocks, and I am assuming massless/frictionless pulleys.

I drew the FBD for each mass, I am just not sure how to connect it all.

So far I am thinking about trying to balance the force on each side of that middle pulley. I have the total mass on the right side that its carrying as 7+2.5? (since half of that 5 is attached the the "floor".) For the left side, I am thinking the mass there now is .5 (half of the 1 is attached to the "ceiling", so I need to get another 9 kgs (and 9 x 9.8 = 88.2 N as T).

Is this completely wrong thinking?

dkgojackets said:
OK here's the one I am really stuck on. I am just not completely sure what's going on. I'm looking for T. The units are kg for mass of the blocks, and I am assuming massless/frictionless pulleys.
You have two strings and therefore two tensions. You need to know how far each mass moves in relation to the other masses. With that information, your FBDs should get you a solvable system of equations.

Still stuck. I think I am missing the effect that the masses have when they are attached to the pulley, not the actual string.

dkgojackets said:
Still stuck. I think I am missing the effect that the masses have when they are attached to the pulley, not the actual string.
I think I misinterpreted the problem. Nothing is moving here? Is that correct?

It is so frustrating when this system freezes up like this. I’ve been frozen out for a long time.
In case I cannot get back in, here is what I have assuming nothing is moving.

TL is the tension in the upper left string
TR is the tension in the lower right string.

T + 1kg*g = 2TL
TL = 7kg*g + 2TR
TR = 5kg*g

Last edited:
Thank you. That makes sense now.

## 1. What is tension downward acceleration?

Tension downward acceleration is a term used in physics to describe the force that is exerted on an object as it is accelerated downwards due to the force of gravity.

## 2. How is tension downward acceleration calculated?

Tension downward acceleration can be calculated using the formula F=ma, where F is the force of tension, m is the mass of the object, and a is the acceleration due to gravity (9.8 m/s^2).

## 3. How does tension downward acceleration affect objects?

Tension downward acceleration can cause objects to accelerate downwards at a constant rate, as long as the force of tension remains constant. This acceleration can also cause objects to gain velocity and potentially reach terminal velocity.

## 4. What are some common examples of tension downward acceleration?

Some common examples of tension downward acceleration include objects falling from a height due to the force of gravity, elevators moving downwards, and objects being pulled down by a pulley system.

## 5. How can tension downward acceleration be applied in real life?

Tension downward acceleration is used in various real-life applications, such as in construction for lifting heavy objects with cranes, in amusement park rides to create thrilling drops, and in sports such as bungee jumping and skydiving. It is also used in everyday activities such as riding an escalator or using a zip line.

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