The most probable reason why the magnets won't stick on the refrigerator is that the body of the refrigerator and the magnets have like poles. If both have negative or both have positive poles facing each other, they will repel. In principle, magnets are attracted to opposite poles and like poles repel.
Answer:
(a) ε = 1373.8.
(b) The wingtip which is at higher potential.
Explanation:
(a) Finding the potential difference between the airplane wingtips.
Given the parameters
wingspan of the plane is = 18.0m
speed of the plane in north direction is = 70.0m/s
magnetic field of the earth is = 1.20μT
The potential difference is given as:
ε = Blv
where ε = potential difference of wingtips
B = magnetic field of earth
l = wingspan of airplane
v = speed of airplane
ε = 1.2 x 18.0 x 63.6
ε = 1373.8
(b) Which wingtip is at higher potential?
The wingtip which is at higher potential.
Explanation:
A chemical reaction in which heat or energy is released is known as an exothermic reaction.
On the other hand, when two objects are placed together and heat flows from hotter object to colder object then this process is known as conduction. Therefore, energy is dissipated in conduction process.
Since energy released released goes into the atmosphere and is not used anywhere.
Thus, we can conclude that when an exothermic reaction releases thermal energy, this energy is usually not useable to do work and it is dissipated by conduction.
Answer:
a) v₂ = 4.2 m/s
b) v₂ = 5 m/s
Explanation:
a)
We will use the law of conservation of momentum here:

where,
m₁ = m₂ = mass of bowling pin = 1.8 kg
u₁ = speed of first pin before collsion = 5 m/s
u₂ = speed of second pin before collsion = 0 m/s
v₁ = speed of first pin after collsion = 0.8 m/s
v₂ = speed of second after before collsion = ?
Therefore,

<u>v₂ = 4.2 m/s</u>
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b)
We will use the law of conservation of momentum here:

where,
m₁ = m₂ = mass of bowling pin = 1.8 kg
u₁ = speed of first pin before collsion = 5 m/s
u₂ = speed of second pin before collsion = 0 m/s
v₁ = speed of first pin after collsion = 0 m/s
v₂ = speed of second after before collsion = ?
Therefore,

<u>v₂ = 5 m/s</u>