Question

Find the coefficient of kinetic friction between a 4.3- block and the horizontal surface on which it rests if an 80 spring must be stretched by 2.7 to pull the block with constant speed. Assume the spring pulls in a direction 13 above the horizontal.

Answer 1

without units, the numerals in your problem are absolutely meaningless.

Answer 2

My bad.

Find the coefficient of kinetic friction between a 4.3-kg block and the horizontal surface on which it rests if an 80 N/m spring must be stretched by 2.7 cm to pull the block with constant speed. Assume the spring pulls in a direction 13 degree above the horizontal.

Answer 3

ok,the force is kx or 80*.027 N

Now look at the components of force.
the vertical component reduces the normal force.

fn=mg-kx*sin13
so friction is mu*(mg-kx*sin13)

and friction force has to equal the horizontal component for the spring, kx*cos13

set them equal, and you have it.

Answer 4

thank you!

may God bless you Bob :)