Kinetic energy:
1) A car traveling down the road has less kinetic energy than a semi-truck and traveling at the same speed because the car's mass is much less than the truck's.
2) A river flowing at a certain speed possesses kinetic energy because the water has a certain mass and it also has velocity.
3) An insect flying has a small amount of kinetic energy because its mass and velocity are relatively small.
Potential Energy:
1) The food we eat has chemical potential energy because as our body digests it, it provides us with energy for basic metabolism.
2) A stretched spring in a pinball machine has elastic potential energy and can move the steel ball when released.
3) When a crane swings a wrecking ball up to a certain height, it gains more potential energy and has the ability to crash through buildings.
<span>(a).the heat trasfer surface area and heat flux on the surface of filament are
Area of Surface= µDL=3.14(0.05cm)(5cm)= 0.785 cm square
qs=Q/Area of surface= 150W/0.785= 191W/cmsq.=1.91x10Âłx10ÂłW/Msq
(b). the heat surface on the surface of heat bulb
Area of surface = 3.14xD²= 3.14(8CM)²= 201.1cm²
qs=Q/Area of surface=150w/201.1cm²=0.75 w/cm²= 7500w/m²
the amount and cost of electrical energy consumed during one period is
Electrical Consumption=QΛt=(0.15 KW)(365X8h/yr)=438 k Wh/yr
Annual cost= 438 kWh/yr)($.08/kWh)= $ 35.04 /yr</span>
The biggest thing you're doing wrong is ignoring the units
when you're working with the quantities.
Now let's look at the rest of the problem:
The formula you used is correct:
Net flux through the surface = (net charge inside) / ε₀
and ε₀ = 8.85 x 10⁻¹² farad/meter.
What's the net charge inside the surface in this problem ?
It's (5.85 x 10⁷ electrons) x (the charge on each electron)
= (5.85 x 10⁷ electrons) x (-1.6 x 10⁻¹⁹ coulomb/electron)
= -9.36 x 10⁻¹² coulomb .
Finally, (net charge inside) / ε₀
= (-9.36 x 10⁻¹² coulomb) / (8.85 x 10⁻¹² farad/meter)
= -1.058 newton-m²/coulomb .
The sign and the significant figures in your answer are correct, so
we can see that you know what you're doing. The only thing left is
the order of magnitude. You most likely took one of the negative
exponents and made it positive. You got an answer that's 10²² too
small. Big deal. You could claim "that's close", and see whether you
can convince a teacher.
My guess would be because the gravity from the Earth's core is constantly pulling the ball towards the ground. It's like the moon. Why doesn't the moon just float away in space? Because Earth's gravitational pull keeps it rotating around it. Therefore, the ball will always be pulled towards the core which keeps it from from rolling forever due to friction. But i may be wrong, even though this a quite a good answer, hope it is right!