All of them are very expensive to install the machinery.
Nuclear energy has no particular negative effect while it's being
generated. But after the fuel is 'used up', and you can't get much
more energy out of it, it's still highly radioactive and dangerous to
people.
We still don't have a good, completely foolproof way to dispose of
the waste material, in a way that will protect people from it for as long
as it stays radioactive (can be thousands of years !).
maximum allowed value of the speed in roller coaster is given as
now from kinematics we can say
here initial speed will be
acceleration is due to gravity
now we can use this to find the height
so maximum allowed height will be 20.4 m
As the headwind comes at the head of the plane, therefore 50 mph headwind slows the plane down.
Thus actual speed of plane with headwind,
Now using the formula ,
Hence plane will take time to complete the distance 1250 mile in 2.5 hours
Answer:
c) is the right answer, since it is the only FALSE statement among the other 4 options, which are TRUE.
Explanation:
Constant "b" stands for the damping term in the oscillatorry equation, which means it is multiplying the first derivate of the movement variable, be it x (distance) or φ (for angular approaches).
Let's exclude the TRUE options:
- a) and d): A very large constant "b" means a high friction into the system, so, if "b" is large enough, it would prevent the system from oscillating (that is, from starting the movement) or, once moving, it may brake it down to zero amplitude within a finite time.
- b) Indeed, a large enough "b" value would mean a supercritical damping case, in which no oscilation takes place. The system breaks despite the real resonance values in frecuency. This means that only for damping below critical values, resonance may occur.
- e) Certainly, the friction may be between two solid bodies. In the case a solid body is inside a fluid environment (liquid or gas), "b" value is proportional to the hidrodynamic or aerodinamic resistance, respectively. This "resistance" depends, amongst other variables, on the shape (fluid distribution) and its cross-sectional area (the wider, the more resistance, the greater "b" shall be).
Finally, as exposed above, a greater "b" value involves a a higher damping, then a higher force against the movement, thus shorter times and quicker damping. This is why opcion c) is the FALSE answer, thus the correct option: it states a wrong principle, opposite to the physics.
Hope that was clear enough! Always think how to exclude answers first, and try to find any option that may be incoherent respect to other(s).
Regards!
A.