Answer:
357.6g
Explanation:
Given parameters:
Density = 12.459g/cm³
Volume of metal = 28.7cm³
Unknown:
Mass of metal = ?
Solution:
The density of a substance is its mass per unit volume.
To find the mass;
Mass of metal = density x volume
Now insert the parameters and solve;
Mass of metal = 12.459 x 28.7 = 357.6g
That can only be happening if the mass mysteriously increased somehow. I'd like to know how in the world THAT happened.
Answer:
ieces A and B must also have the same type of charges
Explanation:
In electrostatics, charges of the same sign repel and charges of different signs attract.
If we apply this to our case, we have that part A and C repel each other, therefore they have the same type of charge.
Also part A and C repel each other, therefore they have the same type of charge.
If we use the transitive property of mathematics, pieces A and B must also have the same type of charges
If it produces 20J of light energy in a second, then that 20J is the 10% of the supply that becomes useful output.
20 J/s = 10% of Supply
20 J/s = (0.1) x (Supply)
Divide each side by 0.1:
Supply = (20 J/s) / (0.1)
<em>Supply = 200 J/s </em>(200 watts)
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Here's something to think about: What could you do to make the lamp more efficient ? Answer: Use it for a heater !
If you use it for a heater, then the HEAT is the 'useful' part, and the light is the part that you really don't care about. Suddenly ... bada-boom ... the lamp is 90% efficient !
Answer:
x = 0.0537 m or 5.37 cm
Explanation:
Given:
spring constant'k'= 4900 N/m
radius 'r' =0.029 m
Area 'A' =r²π = 0.029²π => 2.6 x 
m²
Here, Pressure 'P' is given by,
Pressure = Force / Area
And we know that, for a spring :
F = kx, where k is the spring constant and x is the change in length.
P = kx/A
As P = 101325 Pa
101325 = 4900x / ( 2.6 x )
x = 0.0537 m or 5.37 cm
