# Force to accelerate an object downward faster than g

• Big Tommy C
In summary, the conversation discusses the math behind accelerating an object downwards at a rate of 16 inches in 0.1655 seconds. The individual is trying to determine the necessary force for this acceleration, and it is clarified that the force needed is the mass multiplied by the difference between the acceleration and gravity. The conversation also touches on the concept of adding an extra force upwards to balance the weight of the object for upward acceleration.
Big Tommy C
Hello all.

I am trying to understand the math behind this and keep getting stuck. If I want to accelerate and object downward,lets say 16 inches in 0.1655 seconds , that would be faster acceleration than gravity. I think 29.67 m/s2, so if I calculate force to accelerate at that rate downward, Do I have to subtract 9.8 m/s2 from my acceleration of 29.67 before I calculate the force? IE 29.67-9.8=19.87m/s2 and then I use that acceleration of 19.87 against my mass to determine the force required?

Hoping for some clarification ,Tom

Delta2
I assume the thing is starting from rest and accelerating uniformly, because then you get the ##30 \text{ms}^{-2}## acceleration.

And yes, to determine the additional force you yourself need to apply, you subtract ##g## and multiply by ##m##. That's just because ##F + mg = ma \iff F = m(a-g)##.

Lnewqban, Delta2 and Big Tommy C
Thinking in reverse, in order to accelerate the same mass upwards at a similar rate, you need to add enough extra upwards force to compensate for the downwards force of weight.
The function of that extra force up is only to balance weight: any additional up force will be the only one contributing to up acceleration.

##a=F_{resultant}/mass##

Always think of acceleration as a result of applying a resultant force onto a mass.

Big Tommy C
Yes Lnewqban I had this question a while back, I appreciate the response.

I was able to derive that by simply adding the weight of the load plus the force required to accelerate it on a vector would give me my final total F requirement.

Lnewqban

## 1. How can an object be accelerated downward faster than the acceleration due to gravity?

An object can be accelerated downward faster than the acceleration due to gravity by applying an external force on the object. This force must be greater than the force of gravity pulling the object towards the ground.

## 2. What factors determine the force required to accelerate an object downward faster than g?

The force required to accelerate an object downward faster than g is determined by the mass of the object and the acceleration rate desired. The greater the mass of the object or the higher the desired acceleration rate, the greater the force needed.

## 3. Can an object be accelerated downward faster than g without an external force?

No, an object cannot be accelerated downward faster than g without an external force. The acceleration due to gravity is a constant force acting on all objects and cannot be changed without an external force.

## 4. What is the relationship between force and acceleration in regards to accelerating an object downward faster than g?

The relationship between force and acceleration is directly proportional. This means that as the force applied to an object increases, the acceleration rate also increases. Therefore, to accelerate an object downward faster than g, a greater force must be applied.

## 5. Are there any limitations to accelerating an object downward faster than g?

Yes, there are limitations to accelerating an object downward faster than g. The force required to accelerate an object must not exceed the maximum force that the object can withstand without breaking. Additionally, the acceleration rate must not exceed the maximum acceleration rate that the object can handle without being damaged.

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