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
The angle of refraction would be further less
Answer:
Total energy saving will be 0.8 KWH
Explanation:
We have given there are 50 long light bulbs of power 100 W so total power of 50 bulb = 100×50 = 5000 W = 5 KW
30 bulbs are of power 60 W
So total power of 30 bulbs = 30×60 = 1800 W = 1.8 KW
Total power of 80 bulbs = 1.8+5 = 6.8 KW
Total time = 3 hour
We know that energy 
Now power of each CFL bulb = 25 W
So power of 80 bulbs = 80×25 = 2000 W = 2 KW
Energy of 80 bulbs = 2×3 = 6 KWH
So total energy saving = 6.8-6 = 0.8 KWH
Answer:
The volume of the larger cube is 5.08 g/cm³.
Explanation:
Given that,
Mass of smaller cube = 20 g
Density of smaller cube 
Dylan has two cubes of iron.
The larger cube has twice the mass of the smaller cube.
Density is same for both cubes because both cubes are same material.
The density is equal to the mass divided by the volume.
Where, V = volume
m = mass
We need to calculate the volume of smaller mass
The volume of smaller mass
Now, We need to calculate the volume of large cube
Hence, The volume of the larger cube is 5.08 g/cm³.
