A particle A moves along the line = 30 with a constant velocity ( = 3.0 /) directed parallel to the positive axis (see figure). A
second particle B starts at the origin with zero speed and constant
acceleration ( = 0.40 /2) at the same instant the particle A passes
the axis. What angle between and the positive axis would result in
a collision between these two particles?

The correct answer is  "c".  it is "c" because melting is an endothermic change, and endothermic get's energy from surroundings. 

The correct choice is c

W= fd
where f is an applied force and d is the distance over which it is applied. when a parachuting skydiver is at constant velocity, he is experiencing "terminal velocity", the point at which his acceleration down is canceled out by air resistance. that means that the resisting force of the air is equal to his weight, but in the opposite direction. with this, we can solve for the work done by the force.
w = fd
w = (92.0)(9.81 m/s^2) (325)
w= 2.93 x 10^5 j
the value for work in this case is positive because it is pushing up on the skydiver, who has a downward force of gravity.
therefore the answer is 2.93 x 10^5 j