ako zna neko rijesiti ove zadatke bila bih mu jako zahvalna...na eng.su jer idem u dvojezičnu gimnaziju.

1.a block is placed ona rough wooden plane.it is found that when the plane is tilted 30° to the horizontal,the block will slide down at constant speed.the coefficient of kinetic friction of the block with the plane is?

2.a crate is sliding down an incline that is 35° above the korizontal.if the coefficient of kinetic friction is 0.40 the acceleration of the crate is?

3.a 5 kg crate is resting on a horizontal plank.the coefficient of static friction is 0.50 and the coefficient of kinetic friction is 0.40.after one end of the plank is raised so the plank makes an angle of 25° with the horizontal,the force of friction is?

4.a 5kg crate is resting on a horizontal plank.the coefficient of static friction is 0.50 and the coefficient of kinetic friction is 0.40.after one end of the plank is raised so the plank makes an angle of 30° with the horizontal,the force of friction is?

5.a box rests on a rough board 10m long.when one end of the board is slowly raised to a height of 6m above the other end the box begins to slide.the coefficient of static friction is?

6.a horizontal force of 12N pushes a 0.5kg book against a vertical wall.the book is initially at rest.if the coefficient of static friction is 0.6 and of kinetic is 0.8 which of the following is true?

sad je tu ponuđeno više odgovora ali je točan da je magnitude of frictional force 4.9N.
ali ne znam kako to dobiti...

hvala!