Force = Mass x Acceleration

[Santa_Clause]

I'm so confused right now, it isn't funny.

F = ma.

I know that force is measured in Newtons. Acceleration is measured in m/s squared. What is mass measured in? Grams or kilograms? Can anyone explain the whole equation and give me a couple of examples?

[sweetleaf]

kilograms always. convert the grams to kg.

F = ma lets us work out the forces at work on objects
by multiplying the mass of the object by the acceleration of the object.

Example:
The force at work on a Formula 1 car as it starts a race!
If the F1 car has a Mass of 600kg and an Acceleration of 20m/s/s
then we can work out the Force pushing the car by multiplying
the Mass by the Acceleration like this 600 x 20 = 12000N

F = ma is the second law of motion proposed by Sir Isaac Newton.

http://www.racemath.info/forcesandpressure/what_is_f=ma.htm

Don't forget that the F is always in newtons

we did this in physics like 3 months ago lol

[Santa_Clause]

And then do I use Newtons or Kilonewtons? Mind giving me an example?

[sweetleaf]

always in newtons. hit refresh lol i edited my post

[Santa_Clause]

Click Here (http://www.racemath.info/forcesandpressure/Examples_F=MA.htm).

Have they made a mistake by saying KiloNewtons?

[Hobbit]

Example...

Sally decieded to jump off a building. She is weighs 67kg. Find the force acting on her.
Gravity = 9.8m/s^2
67kg

F=ma => F=mg
F=(67)(9.8)
F=656.6 N

I wish we still got to do this stuff in Physics... it was so easy... :(

[sweetleaf]

idk in my class the answer would still be in N not KN

[Santa_Clause]

Example...

Sally decieded to jump off a building. She is weighs 67kg. Find the force acting on her.
Gravity = 9.8m/s^2
67kg

F=ma => F=mg
F=(67)(9.8)
F=656.6 N

I wish we still got to do this stuff in Physics... it was so easy... :(

I'm still in Grade 10...you only have like 1 year till the end of school.

Thanks for the example. So basically...when I substitute the mass into the equation, it has to be in KiloGrams form. If it says 67 grams, I would have to make that 0.067 Kg, and then do (0.067)(9.8) and get the answer for that? I think I understand it now.

[sweetleaf]

I'm still in Grade 10...you only have like 1 year till the end of school.

Thanks for the example. So basically...when I substitute the mass into the equation, it has to be in KiloGrams form. If it says 67 grams, I would have to make that 0.067 Kg, and then do (0.067)(9.8) and get the answer for that? I think I understand it now.

yea you got it. just plug and chug, mass times acceleration.

[Pwnt by Pwnt]

F = ma
her weight is 67KG as posted by Hobbit, if it was 67G then she would be dead lol ever seen someone who weighed as much as 67 paper clips..? ;)
you need acceleration first but in Hobbit's problem, you can't find it.. because you need the change of velocity and the time.. or V2 or V1 or time and acceleration.. so if her acceleration is 5 then its
F = (67)(5) which is 335 I believe... but her acceleration would never be 5 lol unless she jumped off a toy house ;) but yeah... and btw, don't use "x" to refer to multiplication... because x is usually a variable in physics as in algebra. :) hope it helps...

(answer is 335 N, according to what I said... sooo yeah...)

[Brain]

A newton is equal to one kilogram*meter per second squared
the kilonewtons that the website is talking about is just 1000 newtons ;)
you were just thinking too hard about it and over looking the simple answer
if you need anymore physics help you can pm me or add me on msn
we are just finishing up my physics class and I'm in college going to be a civil engineer, so we take it pretty deep...lol

and if you wanted to find the force that the ground was exerting on you
you just take your mass, times your acceleration (gravity) and there ya go, thats also called the normal force...wait till you get to friction

have fun, physics is really interesting, and can be fun ;)

EDIT:


F = ma
her weight is 67KG as posted by Hobbit, if it was 67G then she would be dead lol ever seen someone who weighed as much as 67 paper clips..? ;)
you need acceleration first but in Hobbit's problem, you can't find it.. because you need the change of velocity and the time.. or V2 or V1 or time and acceleration.. so if her acceleration is 5 then its
F = (67)(5) which is 335 I believe... but her acceleration would never be 5 lol unless she jumped off a toy house ;) but yeah... and btw, don't use "x" to refer to multiplication... because x is usually a variable in physics as in algebra. :) hope it helps...

(answer is 335 N, according to what I said... sooo yeah...)

not really...I'm assuming that Hobbit is assuming that the girl had no initial x velocity (which wouldnt matter because there would be no acceleration in the x anyway because there are no forces acting in the x once she leaves the building, thus projectile motion) and that she did not jump downward off the building, meaning no initial y velocity. So his statement of her acceleration being 9.8 m/s^2 is correct because the only force acting on her is gravity...and an acceleration of 5 downward would never happen unless terminal velocity is reached (for simple equations you remove friction i.e. air) which it isn't, so all y acceleration would be downward at 9.8m/s^2...not 5, ever. So Hobbit is correct, and you are too kinda in your math, but not in your logic

[sweetleaf]

9.8 is the acceleration due to gravity : )

[Santa_Clause]

A newton is equal to one kilogram*meter per second squared
the kilonewtons that the website is talking about is just 1000 newtons ;)
you were just thinking too hard about it and over looking the simple answer
if you need anymore physics help you can pm me or add me on msn
we are just finishing up my physics class and I'm in college going to be a civil engineer, so we take it pretty deep...lol

and if you wanted to find the force that the ground was exerting on you
you just take your mass, times your acceleration (gravity) and there ya go, thats also called the normal force...wait till you get to friction

have fun, physics is really interesting, and can be fun ;)

EDIT:



not really...I'm assuming that Hobbit is assuming that the girl had no initial x velocity (which wouldnt matter because there would be no acceleration in the x anyway because there are no forces acting in the x once she leaves the building, thus projectile motion) and that she did not jump downward off the building, meaning no initial y velocity. So his statement of her acceleration being 9.8 m/s^2 is correct because the only force acting on her is gravity...and an acceleration of 5 downward would never happen unless terminal velocity is reached (for simple equations you remove friction i.e. air) which it isn't, so all y acceleration would be downward at 9.8m/s^2...not 5, ever. So Hobbit is correct, and you are too kinda in your math, but not in your logic

The question says that the acceleration is 0.05 M/s ^ 2.
The mass is 700 Kg.

So the force = 700 * 0.05 = 35 Newtons...why have they written 35000 Newtons?

[Wizzup?]

1 Kilo-newton is just 1*10^3 Newton.

[Brain]

The question says that the acceleration is 0.05 M/s ^ 2.
The mass is 700 Kg.

So the force = 700 * 0.05 = 35 Newtons...why have they written 35000 Newtons?

ummmm, not sure lol :p it must be a mistake!....sorry, I didn't exam the example to closely

[nickienine]

thats pretty freakin genius. but i would say its force times acceleration? yes? im not sure, only in the middle of gr 9 science.