Answer:
<h2>
187,500N/m</h2>
Explanation:
From the question, the kinectic energy of the train will be equal to the energy stored in the spring.
Kinetic energy = 1/2 mv² and energy stored in a spring E = 1/2 ke².
Equating both we will have;
1/2 mv² = 1/2ke²
mv² = ke²
m is the mass of the train
v is the velocity of then train
k is the spring constant
e is the extension caused by the spring.
Given m = 30000kg, v = 4 m/s, e = 4 - 2.4 = 1.6m
Substituting this values into the formula will give;
30000*4² = k*1.6²
The value of the spring constant is 187,500N/m
Work = Force x displacement
Force= 20N
Displacement= 0.75m
W= 20(0.75)
W= 15 Nm
Well, first off, mechanical energy is the sum of kinetic and potential energy in an object that is used to do work. In other words, it is energy in an object due to its motion or position, or both. Heat energy is the result of the movement of tiny particles called atoms, molecules or ions in solids, liquids and gases. Light energy is the only form of energy that we can actually see directly. It is formed through chemical, radiation, and mechanical means. Striking a match stick (mechanical energy) creates fire, which has a ton of heat energy, and produces light too, so the answer, is A. I hope i could help!
