A body weighing 40 lbs starts from rest and slides down a plane at an angle of 30 with the horizontal for which the coefficient of friction f=0.3. How far will it move during the third second?

Help please? :)

Question

A body weighing 40 lbs starts from rest and slides down a plane at an angle of 30 with the horizontal for which the coefficient of friction f=0.3. How far will it move during the third second?

Help please? :)

anonymous · Answer

newtons second kaw state ΣF=ma

anonymous · Answer

so P+f=ma

anonymous · Answer

but f is - since its in the opp direction of motion and 40lb=13 kg so 13g-0.2=13 a

anonymous · Answer

i mean -0.3 not 0.2

anonymous · Answer

wait ill solve it and send you and attachment cause i dont like typing

anonymous · Answer

ok. :) i'll solve it too.

anonymous · Answer

what do you mean by the coefficient of friction is 0.3 ? how could you get friction

anonymous · Answer

thats it

anonymous · Answer

is it correct??

anonymous · Answer

the choices are:
a. 19.63
b. 19.33
c. 18.33
d. 19.99

i don't know,

anonymous · Answer

well if you realize i changed lbs to kg because that is what we do at our place do you keep it on lbs?? or you also do convert to kg?

anonymous · Answer

we convert depending on the most dominant unit in the problem.

anonymous · Answer

ok and concerning friction what does the formula states that includes the coefficient?

anonymous · Answer

F=fN is that?

anonymous · Answer

f is the coefficient of friction,

perl · Answer

you need to find the acceleration

anonymous · Answer

how?