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:
A) 12P
Explanation:
The power produced by a force is given by the equation

where
W is the work done by the force
T is the time in which the work is done
At the beginning in this problem, we have:
W = work done by the force
T = time taken
So the power produced is

Later, the force does six times more work, so the work done now is

And this work is done in half the time, so the new time is

Substituting into the equation of the power, we find the new power produced:

So, 12 times more power.
Instantaneous velocity is defined at a specific value of
time t. It can never be observed or measure. To know a velocity, one must know
its distance and velocity. It is represented by the equation velocity is equal
to delta distance over delta time. The problem above lacks data.
Answer:
<em>C. the blue colour of the Earth's sky</em>
<em></em>
Explanation:
The Pleiades is a cluster of sister stars that are among the closest star cluster to earth.
The reflection nebula of the Pleiades is due to the scattering of the blue light from the hot blue luminous stars that dominate the star cluster. Th blue light is scattered from dust molecules, thought to be predominantly carbon compound like diamond dusts, and other compounds like iron.
The blue colour of the Earth's sky is the closest terrestrial phenomenon to the reflection nebula. On a clear cloudless day, molecules in the air scatter the blue component of light more than the other component colours of white light, giving the sky its characteristic blue coluor.
The common characteristics of the luminous nebula and the Earth's blue sky is that they both have their light scattered by the presence of small particles.
Answer:
As an object accelerates i.e., change it's velocity(either direction or speed), the position of the object depends on two factor; If the acceleration was direction based then it might have a zero displacement for eg: if it travels in circle. or it might have a net displacement if it travels in a straight line, quantitatively
where,
s = displacement
u = initial velocity
v = final velocity
a = acceleration
t = time
Now, for the hypothesis;
There is no direct relationship between fan speed and acceleration but anyways generally speaking if we do have a relationship that with more fan speed we have a larger displacement of air i.e., a more force i.e., greater acceleration
Thus, it can be said, well not exactly scientific, that with a greater fan speed there will be greater acceleration. if fan speed is increased then acceleration will be more.
:)
Explanation: