Question

PLEASE HELP!!!!

Jill has designed a ramp to help her move heavy boxes into a moving truck that she thinks works much better than the one provided by the moving company.  The back of the truck is 1 meter high.  Jill has a ramp that is 3 meters long.  The moving company’s ramp is 2.5 meters long.  Is Jill correct that her ramp has a greater mechanical advantage?  Why or why not?

Answer 1

i need this done today

Answer 2

ok..
do you kno how a ramp gives you a mechanical advantage?! or how does it give you an advantage?!

Answer 3

well... i just started learning this stuff so i really dont know, its kinda confusing

Answer 4

Do you kno what is the meaning of mechanical advantage?

Answer 5

yes its the number of tmes the input force is multiplied by a machine

Answer 6

yes.. so.. that, you put in LESS EFFORT,
but how is that possible?! don't u think its some sort of violation of conservation law?
i mean how can u get something more from something less?

Answer 7

by adding more?

Answer 8

but thats not possible..
well anyways... lets not bother about that now..


so lets say.. u have a certain box of mass m, and you have to lift it up by a height of h

can you tell me how much force you need to put to lift it?

Answer 9

you need to put more force than the weight of the box

Answer 10

well if you put the same force as that of the weight, then u ll be able to JUST lift it.. and thats all we need ya?

so we need to put the force F = mg.. agree?
can you tell me how much Work we do? (is the chapter work and energy done for you?)

Answer 11

uh, i have no idea... and no the work was not done for me

Answer 12

ok then forget about work... now .. lets say you don't have the upper body strength to lift that box ( say you are a very weak girl :D :D)

then what we can do is use a ramp.. lets see how that works


this is a free body diagram..
u see that N and mg are not along the same striaght line anymore..

so .. we have to resolve mg,
i have done mypart.. can u tel me how much will those components which i have shown in the dotted lines?

Answer 13

is this too complicated for you? i hope free body diagrams and force resolution is done for you :O

Answer 14

idk, my mind is like blank right now!

Answer 15

lolz.. so force resolution and all that is not done? how did they derive the expression for mechanical advantage?? do you have some copy of your notes which you can post or something??

Answer 16

not really because im in online school and all my work is on paper... i know its probaly complicated to help me :(

Answer 17

no.. can u like click a snap or something? (if its not too much to ask?)

or you can jste tell me in brief the names of the topics covered.. before this.. ?

Answer 18

i cant do snap chat but the topic name is:

using machines

and then it talks about machines make work easier and it shows me stuff like:

MA=outputforce/inputforce
F out/F in

Answer 19

and then it talks about simple machines and how they work
ex:
inclined plane
lever
wheel and axle
screw
wedge
pulley

Answer 20

ok.. fine.. but when it comes to ramp..
did they derive a formula for mechanical advantage? maybe interms of the length of the ramp or the angle or something?
since you have dealt with forces, have u dealt with vectors?!? and force resolutions?

Answer 21

i think i just gave you the formula which is MA= f out/f in

Answer 22

yea.. correct..

but how will u calculate how much is f out? in your scenario?

Answer 23

and how much the f in ?

Answer 24

but dividing the f in

Answer 25

ok then can u try solving your question..?? calculate F_out, and F_in.. ?!

Answer 26

ok but what is the f out and f in in the problem, im stuck now :(

Answer 27

see.. thats what i was asking you.. haven't they done that in your notes? haven't you solved any ramp problems? or derivations??

Answer 28

nope... :(

Answer 29

have you done forces, and vector resolutions?

Answer 30

which is easier to push???

in case A or in cas B ?