Answer:
The object's velocity would increase due to the change in force.
Explanation:
I., II., and IV. are examples of acceleration. III. isn't.
Explanation:
Given that,
The slope of the ramp, 
Mass of the box, m = 60 kg
(a) Distance covered by the truck up the slope, d = 300 m
Initially the truck moves with a constant velocity. We know that the net work done on the box is equal to 0 as per work energy theorem as :

u and v are the initial and the final velocity of the truck
(b) The work done on the box by the force of gravity is given by :

Here, 


W = -24550.13 J
(c) What is the work done on the box by the normal force is equal to 0 as the angle between the force and the displacement is 90 degrees.
(d) The work done by friction is given by :


Hence, this is the required solution.
Answer: My initial velocity is 5 m/s.
Explanation:
In this case, momentum can be conserved.
initial momentum = final momentum
Since both the bodies come to rest after collision,
Final momentum = 0
Let my velocity be v, and mass, m1 = 60 kg
Friend's mass, m2 = 100 kg
Friend's velocity, v2 = 3 m/s
Intial momentum = m1v + m2v2
= 60v + 300
Conserving momentum,
60v + 300 = 0
v= -5 m/s
( Negative sign indicates that me and my friend are moving in opposite directions that is towards each other)