Arock is thrown upward from the level ground in such a way that the maximum height of its flight is equal to its horizontal range r.
(a) at what angle θ is the rock thrown? °
(b) in terms of its original range r, what is the range rmax the rock can attain if it is launched at the same speed but at the optimal angle for maximum range? rmax =
(c) would your answer to part (a) be different if the rock is thrown with the same speed on a different planet? yes no

Answer

a) For the rock

b) for maximum range

c) The value of θ is the same on every planet as g divides out.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards