Answer:
Position A/Position E
, 
Position B/Position D
, 
, for 
Position C
, 
Explanation:
Let suppose that ball-Earth system represents a conservative system. By Principle of Energy Conservation, total energy (
) is the sum of gravitational potential energy (
) and translational kinetic energy (
), all measured in joules. In addition, gravitational potential energy is directly proportional to height (
) and translational kinetic energy is directly proportional to the square of velocity.
Besides, gravitational potential energy is increased at the expense of translational kinetric energy. Then, relative amounts at each position are described below:
Position A/Position E
,
Position B/Position D
, , for
Position C
,
<span>Taking into account the information above, we know the average mass of the bucket of water may be m=20-5/2=17.5kg. As the bucket of water is pulled at a "constant velocity" the work required to raise the bucket to the platform transformed into the potential energy of the bucket of water. That is why it should be W=mgh=17.5*9.8*40=6860J</span>
Microwave<span> ovens are so quick and efficient because they channel </span>heat<span> energy directly to the molecules (tiny particles) inside </span>food<span>. </span>Microwaves heat food<span> like the sun heats your face—by radiation. A </span>microwave<span> is much like the electromagnetic waves that zap through the air from TV and radio transmitters</span>
Answer: 10Nm or 10J
Explanation:
Given the following :
Force (f) = 5
Distance (d) = 2m
Calculate the kinetic energy assuming no friction
Work done = force × distance
Work done = 5N × 2m = 10Nm
Recall :
Work done = ΔK.E ( change in kinetic energy)
Therefore, kinetic energy of the book after sliding = ΔK. E, which is equal to work done.
Hence, K. E of book after sliding is 10Nm
A shovel would classify as choice (A) because the head of the shovel is the wedge while the body of the shovel is the lever
