Is Force Definable with Given Velocity, Time, and Displacement Data?

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Force cannot be defined solely with the provided data of height, time, and velocity, as mass is a necessary component in the calculation. The discussion highlights inconsistencies in the kinematic data, particularly regarding the interpretation of displacement and acceleration. It emphasizes that acceleration should reflect gravitational force, which is typically around 9.8 m/s², rather than the calculated 2.5 m/s². Additionally, the concept of distance as a scalar quantity is clarified, indicating that displacement should be expressed correctly in the context of direction. Ultimately, without mass, the calculation of force remains incomplete and undefined.
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Can we define force if ...

Homework Statement


Can we define force if a body from high of ##h_1=4m## goes down to ##h_2=−3m##, for time ##t=4s##, and with velocity of ##v=10\frac{m}{s}##. The acceleration would be ##a=\frac{v}{t}=\frac{10\frac{m}{s}}{4s}=2.5 \frac{m}{s^2}.## Can we define the force using these things? If yes, let me know the formula, if no, let me know :)

Homework Equations


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The Attempt at a Solution


none.
 
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F = ma, you need the mass as well as acceleration to find the force
 


I know ##F=ma##, but, I have the acceleration, but I don't want mass, I want to know if there's a way to find the Force with distance between two highs , with a velocity for a set time.
 


-Physician said:
Can we define force if a body from high of ##h_1=4m## goes down to ##h_2=−3m##, for time ##t=4s##, and with velocity of ##v=10\frac{m}{s}##. The acceleration would be ##a=\frac{v}{t}=\frac{10\frac{m}{s}}{4s}=2.5 \frac{m}{s^2}.##
This kinematic data doesn't seem consistent. Did you just make it up?
Can we define the force using these things?
No.
 


Yeah, I made it my self, And I see you can't because ##m ,m , s, \frac{m}{s}## wouldn't be able to make ##N## (Newton) or ##kg\frac{m}{s^2}## which is ##kg\frac{m}{s^2}=N##
 


-Physician said:

Homework Statement


Can we define force if a body from high of ##h_1=4m## goes down to ##h_2=−3m##, for time ##t=4s##, and with velocity of ##v=10\frac{m}{s}##. The acceleration would be ##a=\frac{v}{t}=\frac{10\frac{m}{s}}{4s}=2.5 \frac{m}{s^2}.## Can we define the force using these things? If yes, let me know the formula, if no, let me know :)


Homework Equations


none


The Attempt at a Solution


none.

Way too many errors in it.
Firstly you say that object goes from
h1=4m goes down to h2=−3m ?

How can you say that distance will be -3m ? Distance is scalar !
Secondly , yes we can define displacement to be negative with reference to direction but here body is falling uni-directionally. You have to say that body is falling from distance of 4m to 3m.

Again another error : If body is falling downwards then acceleration will be 9.8 or 10m/s2 i.e constant value. This further implies that the velocity of body will keep on increasing by 9.8 or 10m/s , every second. You just can't say that velocity of body will be uniform here in this case.

Again acceleration is rate of change in velocity , not velocity by time.
And lastly , out of curiosity : Are you assuming another planet where acceleration is 2.5m/s2 ?:biggrin:

You CANNOT define FORCE without using or taking MASS of object in ACCOUNT.
 
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Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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