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:
Catastrophic theories
Explanation:
The theory of catastrophe is a collection of methods used to analyze and describe the ways in which a system can experience sudden significant behavioral changes when one or more of the variables that govern it are continuously modified.
Georges Louis de Buffon suggested in 1745 the first destructive theory — that a comet pulled material from the Sun to form the planets.
Therefore the answer is -
Catastrophic theories
.9736 x 1024 kg. That’s a big number, so let’s write it out in full: 5,973,600,000,000,000,000,000,000 kg. You could also say the Earth’s mass is 5.9 sextillion tonnes and the mass of Mars is 7.08 x 1020 tons or 6.42 X 1020 metric tons
Answer: K-core , 1s orbital
Explanation: Electron of Hydrogen atom has lowest energy
when it is in K core (1s-orbital)