Movement of a Body on horizontal surface

AI Thread Summary
A body on a horizontal surface moves under a horizontal force equal to 60% of its weight, and the task is to determine the total time of movement after traveling 24 meters. There is confusion regarding whether the horizontal force refers to the tractive force or the resultant force after accounting for friction. Calculations suggest an acceleration of 6 m/s², but attempts to find the time of movement yield varying results between 1.7 and 2.8 seconds, while the textbook states the answer is 6 seconds. The discussion highlights that the problem involves a phase of acceleration followed by constant velocity, but insufficient information about friction complicates the solution. Clarification on the problem's parameters is necessary to reach a definitive answer.
inv4lid
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Homework Statement


A body that is on a horizontal surface begins to move under the action of horizontal force equal to 60% of its weight. Force acts for a while, then stops acting. Determine the total time of movement if the body has traveled a distance of 24m.

Homework Equations


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I'm not really sure about the "horizontal force". Is it the tractive force or is it the resultant of the difference between the tractive and friction one?
I tried like both(but i really assume the horizontal is the resultant force) and from there we can probably get the acceleration.

The Attempt at a Solution


R = Ft - Ff = ma;
60% = 0,6;
where g is 10N/kg
0,6 m*g = ma;
6m = ma;
a = 6 (m/s2);

I've tried using that formula:
v12 - v02 = 2as
v1 - v0 = √(2as)
We don't know though any of speeds.
s = (v0 + v1)t/2
from there:
48 = (v0 + v1)t
S = v0t + a/2 * t2
24 = v0t + 3t2
tried more things but all attempts led to nothing.

Any help would be appreciated, thanks!
 

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What was the velocity of the body before it “begins to move?”

Check your algebra on solving for the final velocity.
 
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Chestermiller said:
What was the velocity of the body before it “begins to move?”

Check your algebra on solving for the final velocity.
It was 0, yes, i know.
I got some answers between 1,7 and 2,8 seconds. By the way, the end of the book says the true answer is 6s
The problem also belongs to the category of "simple problems", so I think the solution shouldn't be so
difficult. Usually, the problems of this category are solved in 1-2 steps.
 
inv4lid said:
A body that is on a horizontal surface begins to move under the action of horizontal force equal to 60% of its weight. Force acts for a while, then stops acting. Determine the total time of movement if the body has traveled a distance of 24m.
The wording strongly suggests that the "total movement" is made up of a period of constant acceleration while the force is applied, plus a further period of constant velocity. An answer of 6 seconds would then be feasible, but if this is correct then there is insufficient information to deduce it.
Please check you have provided all the information in the question.
 
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Friction isn't mentioned in the problem statement.
 
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 .
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