Answer:
energy can move from one location to another, the particles of matter in the medium return to their fixed position. A wave transports its energy without transporting matter.
Answer and Explanation: Kinetic energy is related to movement: it is the energy an object possesses during the movement. it is calculated as:

For the object thrown in the air:
![K=\frac{1}{2}.2.[v(t)]^{2}](https://tex.z-dn.net/?f=K%3D%5Cfrac%7B1%7D%7B2%7D.2.%5Bv%28t%29%5D%5E%7B2%7D)


Kinetic energy of the object as a function of time: 
Potential energy is the energy an object possesses due to its position in relation to other objects. It is calculated as:

For the object thrown in the air:



Potential energy as function of time: 
Total kinetic and potential energy, also known as mechanical energy is
TME =
+ (
)
TME = 1752
The expression shows that total energy of an object thrown in the air is constant and independent of time.
Kinetic Energy,K.E=1/2MV²
mass,m=16kg
velocity,v=4m/s
K.E=1/2×16×4²
=128kgm²/s²
=128 Joules
Power = work / time = 8000J / 20s = 400W
Answer:
Option D
Explanation:
The work done can be given by the mechanical energy used to do work, i.e., Kinetic energy and potential energy provided to do the work.
In all the cases, except option D, the energy provided to do the useful work is not zero and hence work done is not zero.
In option D, the box is being pulled with constant velocity, making the acceleration zero and thus Kinetic energy of the system is zero. Hence work done in this case is zero.