How do you find force?

Question

how do u find the amount of force I would need with each turn of the handle and total amount of force for a screw jack or jack screw to raise books at a distance of 20 cm?
pitch=2 cm.
books=10 kg
distance=20 cm.
force=circumference of about 150 cm.

to find input force- 10kg*20 cm./2*3.142*radius (75)
so that with be 200/471= 0.42

to find the total amount would be 471/0.42=1121.43

if i used the same about of books with a pulley system. which of the machines has a greater mechanical advantage?

pulley system would be ?

Answer 1

Try energy in equal energy out or vice versa.

Energy in =mgh
m - mass of the books
g - gravitational acceleration (9.81 m/s^2)
h - height or displacement

this the amout of energy we need to raise the books.

Pitch means that every turn we will raise th eboocs by 2 cm so it will take 10 turns.


you have to provide work along the circular path of the circumference

the w=Fs

Now we can say that 1/10 of total potential energy =Fs

or

mgh /10=Fs
F=mgh /(10s)
F=10 x 9.81x .2/(10 x 1.5)=1.308N (newtons)
(to be consistent it is advisable to always convert units to the same scales. In this case Kilogram, Meter Second … system or the International System of Units (ISU)