# Calculating Force Applied to an Object of 100kg Moved 1m in 5s

• I
• Chandrasekar
In summary, the conversation revolved around finding the amount of force applied to an object that is moved or lifted to a certain distance and time. The use of SUVAT equations, acceleration, velocity, and weight were discussed. It was mentioned that the question needs to be specified fully in order to get a correct answer. However, due to a lack of specific data, it was difficult to determine the exact question and solve the problem accurately. f

#### Chandrasekar

TL;DR Summary
how to find how force applied on an object?
if an object of 100kg is moved or lifted to a distance of 1m taken 5s, then how can i find the amount of force applied to the object.
in every problem i noticed, force value is given to find the Workdone and the Power.
I think it is simple problem, but i can't find it simple. can anyone clear this problem?

Use one of the SUVAT equations to find the acceleration.
You have the distance travelling in a set time.

malawi_glenn
Why is time relevant?

What is the final speed of the object?

One note: if not given a velocity (acceleration) profile you will have to make your own and there are an infinite number of ways to get from point A to point B.

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nasu, Lord Jestocost and erobz
If you know distance and time, you can calculate average acceleration.
One solves the problem one is given, not the problem one wants.
I was asking the OP in order to help him/her figure it out.

Average acceleration? That depends on the initial and final velocities, not displacement or time.

In order to lift an object of mass 100 kg upwards, should I ignore gravity?

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russ_watters
...if an object of 100kg is moved or lifted to a distance of 1m taken 5s, then how can i find the amount of force applied to the object.
The initial or final velocity are not specified.
If the mass was initially travelling upwards with a fixed velocity of 0.2 m/s, and maintained that upward velocity throughout the process, then would the force not be; F = m·g = 980 N.

jbriggs444 and malawi_glenn
TL;DR Summary: how to find how force applied on an object?

if an object of 100kg is moved or lifted to a distance of 1m taken 5s, then how can i find the amount of force applied to the object.
There are two different questions here. If the object is moved over a (horizontal) distance and there's no friction AND we assume constant acceleration then the SUVAT equations will tell you that acceleration. Then the Force is ma.
If it's lifted then you need that same force plus the weight of the object. Of course, we are assuming that the object starts off stationary. To get the answer, the question needs to be specified fully.

Any decent text book will (or should) give you questions that are properly defined and for which there is just one correct answer but, if you are trying to deal with a practical situation of your own then defining the question is more up to you - we've all had the experience of getting more than one answer to this sort of problem and then had to go back and decide what the question was exactly. Can be difficult, sometimes, particularly in real life situations with motor cars and electric motors where you just don't expect constant acceleration. SUVAT goes out of the window for a start.

Sorry guys for late replay.

russ_watters said:
One note: if not given a velocity (acceleration) profile you will have to make your own and there are an infinite number of ways to get from point A to point B.
Baluncore said:
The initial or final velocity are not specified.

considering constant velocity. then what do i do next?. sorry for my inability to understand.

Baluncore said:
If the mass was initially travelling upwards with a fixed velocity of 0.2 m/s, and maintained that upward velocity throughout the process, then would the force not be; F = m·g = 980 N.

sorry, is this a question for me?.

sophiecentaur said:
If it's lifted then you need that same force plus the weight of the object. Of course, we are assuming that the object starts off stationary. To get the answer, the question needs to be specified fully.
sophiecentaur said:
if you are trying to deal with a practical situation of your own then defining the question is more up to you - we've all had the experience of getting more than one answer to this sort of problem and then had to go back and decide what the question was exactly.

sorry, i don't have definite data to ask correct question with my understanding. if anyone says 'i have missed this data to solve this problem with this formula' it will be easy for me to understand - i think.

sophiecentaur said:
If the object is moved over a (horizontal) distance and there's no friction AND we assume constant acceleration then the SUVAT equations will tell you that acceleration. Then the Force is ma.

i have got a=0.08 by considering u=0 using formula s=ut+0.5at^2. then got F=8N, is this correct? do i have to add this with weight of the object?[/QUOTE]

Last edited by a moderator:
Sorry guys for late replay.

considering constant velocity. then what do i do next?. sorry for my inability to understand.

sorry, is this a question for me?.

sorry, i don't have definite data to ask correct question with my understanding. if anyone says 'i have missed this data to solve this problem with this formula' it will be easy for me to understand - i think.

i have got a=0.08 by considering u=0 using formula s=ut+0.5at^2. then got F=8N, is this correct? do i have to add this with weight of the object?
Is this a homework problem? If it is, is this the full problem statement? You don’t seem to have connected the dots on what was told to you, and everyone is trying to make an educated guess as to what the full problem statement is supposed to be. We need some clarification.

malawi_glenn, sophiecentaur, SammyS and 1 other person
this is not a
Is this a homework problem? If it is, is this the full problem statement? You don’t seem to have connected the dots on what was told to you, and everyone is trying to make an educated guess as to what the full problem statement is supposed to be. We need some clarification.
this is not a homework problem, just questioned myself on how to find it.

I think i'm unable find the pattern in the dots.

i humbly request someone to explain my misconception on this topic.

For the 5 seconds the mass is being moved, you must support it against gravity with a force of; F = m·g = 980 N.

NOW you must specify the initial and final velocities.
If they are zero, then you must use a force to accelerate the mass, and then an opposite force to decelerate the mass, so that it moves a total of 1 metre in 5 seconds.

The acceleration force will be the negative of the deceleration force, so they will cancel. So the average force during the movement will be; F = m·g = 980 N.

Chandrasekar
this is not a

this is not a homework problem, just questioned myself on how to find it.

I think i'm unable find the pattern in the dots.

i humbly request someone to explain my misconception on this topic.
Homework or not, we aren't going to do it for you. You got a lot of good responses and need to make an effort to address them.

Chandrasekar
TL;DR Summary: how to find how force applied on an object?

if an object of 100kg is moved or lifted to a distance of 1m taken 5s, then how can i find the amount of force applied to the object.
in every problem i noticed, force value is given to find the Workdone and the Power.
I think it is simple problem, but i can't find it simple. can anyone clear this problem?
You need to learn physics to do physics.

vanhees71