a block of mass 20kg is held in equilibrium on a plane by means of a string which is at an an angle of 25° to the greatest slope of the plane. the plane is at 40° to the horizontal.
show that the tension in the string is about 142N
i thought this would be pretty straightforward but i just don't get 142N! i mostly used 200cos60° = Tcos25° but this doesn't wrok, why? are there forces i am missing? no friction btw