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
Answer:


Explanation:
Given:
- width of door,

- height of the door,

- thickness of the door,

- mass of the door,

- torque on the door,

<em>∵Since the thickness of the door is very less as compared to its other dimensions, therefore we treat it as a rectangular sheet.</em>
- For a rectangular sheet we have the mass moment of inertia inertia as:



We have a relation between mass moment of inertia, torque and angular acceleration as:



Answer:
The current is 2.0 A.
(A) is correct option.
Explanation:
Given that,
Length = 150 m
Radius = 0.15 mm
Current density
We need to calculate the current
Using formula of current density


Where, J = current density
A = area
I = current
Put the value into the formula


Hence, The current is 2.0 A.
Answer: Taxpayers
Explanation:
Taking alcohol before driving or while driving is dangerous and has resulted in lots of accidents and deaths. Alcohol tampers with the normal functioning of the brain, and also impairs ones reasoning.
Alcohol impaired driving cases handled by government officials are paid for by the taxpayers. A tax is the levy that the people in the country pays. Those funds are used in handling different government objectives and this is one of such ways.