Magnetic fields surround magnets. They attract or repel, depending on the charge of the object in it.
Answer:
a) 633.39 J
b) 0.28
Explanation:
a)The kinetic energy of the player = 
Work done by friction = energy change of the player
=
= 633.9 J
b) Assuming the frictional force stays constant,
Work done by friction = Frictional force×distance
Frictional force = kinetic friction(μ)×normal reaction
Normal reaction = weight = mass×gravitational acceleration ( g=10m/s2 )
Combining these equations
633.9 = F×3.4 ⇒ F = 186.44 N
F = μmg ⇒ μ = F/mg
= 186.44/670
= 0.28
1. calculate the value of acceleration that objects gains in that period of time
•calculating acceleration
5.50 = 1/2at^2
5.50*2/t^2 = a
11.00/0.657 = a
16.74=a
now you got the acceleration
2. you have laws of gravitation for that
g = Gm/r^2
where g is the acceleration value
16.74 = 6.754*10^-11 × m/ 6.28*10^4
105.14*10^4 /6.754*10-11 = m
15.567*10^15 = m
that would be the mass of the planet ...
Explanation:
Below is an attachment containing the solution.
long does it take to boil away 2.40 kg of the liquid.
Boiling point of He is 
Latent heat of vapourization 
Power of electrical heater 
mass of liquid is 
amount of heat required to boil

Power 

The heat or energy that is absorbed or released during a substance's phase shift is known as latent heat. It could go from a solid to a liquid or from a liquid to a gas, or vice versa. Enthalpy, a characteristic of heat, is connected to latent heat.
The heat that is used or lost as matter melts and transitions from a solid to a fluid form at a constant temperature is known as the latent heat of fusion.
Due to the fact that during softening the heat energy anticipated to transform the substance from solid to fluid at air pressure is the latent heat of fusion and that the temperature remains constant during the process, the "enthalpy" of fusion is a latent heat. The enthalpy change of any quantity of material during dissolution is known as the latent heat of fusion.
For learn more about Latent heat of vaporization, visit: brainly.com/question/14980744
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