Answer: Option (c) is the correct answer.
Explanation:
It is known that the expression for potential energy related to charges and distance between their separation is as follows.
where, 
and 
are two charges
r = distance of separation between the charges
k = electrostatic constant
So, when both the charges are carry the same charge and r is small then the value of potential energy will be positive in nature.
Whereas if the distance of separation between the charges is infinitely large then the potential energy calculated will be zero everywhere.
Thus, we can conclude that the statement one object is negatively charged and the other one is positively charged, is incorrect.
Answer:
Distance 5 km, Displacement 3 km east
Explanation:
The molecules of the perfume diffuse through the room at a certain critical concentration and later are detected by our noses.
Answer:
(A) 374.4 J
(B) -332.8 J
(C) 0 J
(D) 41.6 J
(E) 351.8 J
Explanation:
weight of carton (w) = 128 N
angle of inclination (θ) = 30 degrees
force (f) = 72 N
distance (s) = 5.2 m
(A) calculate the work done by the rope
- work done = force x distance x cos θ
- since the rope is parallel to the ramp the angle between the rope and
the ramp θ will be 0
work done = 72 x 5.2 x cos 0
work done by the rope = 374.4 J
(B) calculate the work done by gravity
- the work done by gravity = weight of carton x distance x cos θ
- The weight of the carton = force exerted by the mass of the carton = m x g
- the angle between the force exerted by the weight of the carton and the ramp is 120 degrees.
work done by gravity = 128 x 5.2 x cos 120
work done by gravity = -332.8 J
(C) find the work done by the normal force acting on the ramp
- work done by the normal force = force x distance x cos θ
- the angle between the normal force and the ramp is 90 degrees
work done by the normal force = Fn x distance x cos θ
work done by the normal force = Fn x 5.2 x cos 90
work done by the normal force = Fn x 5.2 x 0
work done by the normal force = 0 J
(D) what is the net work done ?
- The net work done is the addition of the work done by the rope, gravitational force and the normal force
net work done = 374.4 - 332.8 + 0 = 41.6 J
(E) what is the work done by the rope when it is inclined at 50 degrees to the horizontal
- work done by the rope= force x distance x cos θ
- the angle of inclination will be 50 - 30 = 20 degrees, this is because the ramp is inclined at 30 degrees to the horizontal and the rope is inclined at 50 degrees to the horizontal and it is the angle of inclination of the rope with respect to the ramp we require to get the work done by the rope in pulling the carton on the ramp
work done = 72 x 5.2 x cos 20
work done = 351.8 J
<span>The density of the energy that is transported under the waves under the ocean surface is about five times higher compared to the wind energy 20 meter (about 65 feet) above. In other words, the amount of energy in a single wave is very high. However it turns out that when they tried to make the high power of the waves to power things in a house it only made it past the first few stages there were very few that made it to some stages. This started taking place in around 2001. hope this helped if not let me know and i could explain more:)
</span>
