a yoyo in someones hand is an example of potential energy
The answer for this is yes.
Answer:
k1 + k2
Explanation:
Spring 1 has spring constant k1
Spring 2 has spring constant k2
After being applied by the same force, it is clearly mentioned that spring are extended by the same amount i.e. extension of spring 1 is equal to extension of spring 2.
x1 = x2
Since the force exerted to each spring might be different, let's assume F1 for spring 1 and F2 for spring 2. Hence the equations of spring constant for both springs are
k1 = F1/x -> F1 =k1*x
k2 = F2/x -> F2 =k2*x
While F = F1 + F2
Substitute equation of F1 and F2 into the equation of sum of forces
F = F1 + F2
F = k1*x + k2*x
= x(k1 + k2)
Note that this is applicable because both spring have the same extension of x (I repeat, EXTENTION, not length of the spring)
Considering the general equation of spring forces (Hooke's Law) F = kx,
The effective spring constant for the system is k1 + k2
Energy transfer by waves: two primary modes = (electromagnetic waves, compression/transverse waves propagating through a medium)
1) electromagnetic waves:
Using a particle model for the wave (photons for light), energy transfer is similar to that by discrete moving object -- particles carry the energy from one place to another in the absence of a medium.
Energy delivery: discrete moving object uses inertia and momentum to transfer the energy from itself to the target. Photons are massless, so the energy delivery mechanism must be different.
2) compression/transverse waves propagating through a medium:
Energy passes through the medium with little to no net flow of the medium itself. In transverse water waves, when the energy wave passes by, to first order, the water particles move in vertical circular paths. This is different from energy transfer by a moving object in that the moving object must displace itself to the target position in order to deliver the energy -- resulting in a net flow of object material.