Force Problem - How do i get the inclination?

[rose123456789]

A 10.0 kg object is resting on a horizontal surface with coefficient of friction of 0.7. Determine the minimum force F that can move this object. At what inclination should force F be applied? Present your answer in nearest hundredths.

I don't know how where to start?, How do i get the inclination ? thanks for the help

 

[SataSata]

I'm pretty sure there's an equation for this and you already have half of the variables. A quick google search would show you the answer. Try searching for coefficient of friction and in this case it's probably static friction.

 

[rose123456789]

ok thanks!

 

[haruspex]

ok thanks!

Does that mean you found the answer?
Really you should be figuring this out for yourself using free body diagrams and applying the force balance equations. You'll learn more that way than looking the answer up. Besides, it often happens that there is some subtle difference between the problem you are trying to solve and the one you find lying around on the net.

 

[rose123456789]

oh no, I'm still figuring out the answer

 

[rose123456789]

Does that mean you found the answer?
Really you should be figuring this out for yourself using free body diagrams and applying the force balance equations. You'll learn more that way than looking the answer up. Besides, it often happens that there is some subtle difference between the problem you are trying to solve and the one you find lying around on the net.

i'm still figuring out the answer

 

[haruspex]

oh no, I'm still figuring out the answer

Ok. Have you drawn yourself a force diagram? What forces do you have, and in what directions do they act?

 

[rose123456789]

Ok. Have you drawn yourself a force diagram? What forces do you have, and in what directions do they act?

i calculated that the normal force is 98N and the friction force is 68.6N . and i don't know what is next

 

[rohitjinnu16]

i calculated that the normal force is 98N and the friction force is 68.6N . and i don't know what is next

just take angle as some 'x' and force as F and write the equations .u wil get as
Fcos x=0.7(w-F sinx)
solving this u wil get the eq. as 10 cos x+7 sin x should me max for the force to be minimum.
and solving x=34.99 degrees

 

[rose123456789]

just take angle as some 'x' and force as F and write the equations .u wil get as
Fcos x=0.7(w-F sinx)
solving this u wil get the eq. as 10 cos x+7 sin x should me max for the force to be minimum.
and solving x=34.99 degrees

how did you get 10 cos x +7 sin x

 

[rose123456789]

just take angle as some 'x' and force as F and write the equations .u wil get as
Fcos x=0.7(w-F sinx)
solving this u wil get the eq. as 10 cos x+7 sin x should me max for the force to be minimum.
and solving x=34.99 degrees

ohhh ok i got it now thanks

 

[rohitjinnu16]

ohhh ok i got it now thanks

kk fn.

 

[rose123456789]

kk fn.

hahahahaha thanks a lot

 

[rose123456789]

kk fn.

ok I'm a bit lost could you explain how did you get 10 cos x +7 sin x

 

[rohitjinnu16]

ok I'm a bit lost could you explain how did you get 10 cos x +7 sin x

F cos x =0.7(w-F sin x)
F cos x/0.7=w-F sin x
F((cos x/0.7)+sin x)=w
F(10 cos x+7 sin x)/7=w
F=(7w)/(10 cos x+7 sinx)

 

[haruspex]

i calculated that the normal force is 98N and the friction force is 68.6N . and i don't know what is next

You have not allowed for the applied force being at some angle to the horizontal. What will that do to the normal force?