Register to reply

Acceleration in function of time and distance

by sinnet3000
Tags: acceleration, distance, function, time
Share this thread:
May1-12, 12:57 AM
P: 2
Here is something that has got me confused a lot of times.

Suppose I have a distance of 11m and a time of 5 seconds and I want to know acceleration.

I would say that [itex] a = v / t[/itex] and [itex] v = d / t [/itex] so I could plug the second equation to the first equation having: [itex]a = d / t^2[/itex]

Therefore I have [itex] a = 11 / 5^2m/s^2[/itex] but that is the wrong answer.

We also have [itex]x=x_0+v_0 t+1/2 at^2[/itex] so: [itex] a = 2d / t^2 [/itex] which in that case is [itex] a = 2(11) / 5^2 [/itex] and this is right.

But why is the reason that distance should be the double of it?? Can someone explain me please??

Thank you
Phys.Org News Partner Physics news on
Engineers develop new sensor to detect tiny individual nanoparticles
Tiny particles have big potential in debate over nuclear proliferation
Ray tracing and beyond
May1-12, 01:00 AM
P: 757
acceleration is not v/t and velocity is not d/t you got these wrong. Go back to the definition.
May1-12, 02:53 AM
Sci Advisor
HW Helper
P: 9,876
In case it's not clear, Curl is telling you a = v/t is only true for constant acceleration, and where v is a change in speed and t the time over which it happened. Similarly v = d/t is for constant speed etc. Since you have acceleration, the second is definitely not valid.

May1-12, 07:27 AM
P: 5,632
Acceleration in function of time and distance

We also have x=x0 +v0 t+1/2at2

IS a correct this case, however, the nomenclature looks a bit different from those explained in the previous post. You always need to consider the applicability of an equation you wish to use against the conditions in the problem you are this equation
x0 is a fixed initial distance; v0 is a constant velocity and a is a constant acceleration....[it's potentially confusing when two of the constants have a subscript yet acceleration doesn't even though it is also a [fixed] constant.]
May3-12, 12:50 AM
P: 2
Thank you guys

Register to reply

Related Discussions
Distance unknown, have acceleration time and another distance Introductory Physics Homework 7
Acceleration as a function of position, and time taken to travel a distance Introductory Physics Homework 3
Acceleration as a function of distance Introductory Physics Homework 5
Acceleration as a Function of Distance Introductory Physics Homework 1
Acceleration as a function of distance to function of time Calculus & Beyond Homework 22