Answer:
232 J/K
Explanation:
The amount of heat gained by the air = the amount of heat lost by the tea.
q_air = -q_tea
q = -mCΔT
q = -(0.250 kg) (4184 J/kg/ºC) (20.0ºC − 85.0ºC)
q = 68,000 J
The change in entropy is:
dS = dQ/T
Since the room temperature is constant (isothermal):
ΔS = ΔQ/T
Plug in values (remember to use absolute temperature):
ΔS = (68,000 J) / (293 K)
ΔS = 232 J/K
Answer:
The tension force in the supporting cables is 7245N
Explanation:
There are two forces acting on the elevator: the force of gravity pointing down (+) with magnitude (elevator mass) x (gravitational acceleration), and the tension force of the cable pointing up (-) with an unknown magnitude F. The net force is the sum of these forces:
We are given the resulting acceleration along with the mass, i.e., we know the net force, allowing us to solve for F:
The tension force F in the supporting cables is 7245N
Scientific knowledge itself cannot have a positive or negative impact on society per se. What can have a negative or positive impact is how this knowledge is being used.
While we all enjoy a beter life due to advancements in medicine and technology for example, this was because people decided they would put certain scientific discoveries into practice and spread them among the people.
The same thing can also be said for negative scientific discoveries. While energy produced in atomic power plants per se isn't harmful, when making an atomic bomb out of it, it can be disastrous. It was the intention of doing something evil with it that might have had a negative impact on society, not the knowledge itself.
Answer
Given,
Length of the wire,L = 31 cm = 0.31 m
mass of the wire, m = 9 g = 0.009 Kg
Current in the wire,I = 7 A
Magnetic field strength, B= ?
Equating magnetic force to the weight of the wire.
B = 0.0407 T
For Force to be upward magnetic field direction should be outward of the plane of paper.
· free fall is any motion of a body where gravity is the only forceacting upon it. In the context of general relativity, where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on it.
