Answer:
A. a material burns out when current is excessive
You would want it to be greater than D. friction force
It needs be greater than the friction applied to it.
Answer:
Explanation:
a ) Time period T = 2 s
Angular velocity ω = 2π / T
= 2π / 2 = 3.14 rad /s
Initial moment of inertia I₁ = 200 + mr²
= 200 + 25 x 2.5²
=356.25
Final moment of inertia
I₂ = 200 + 25 X 1.5 X 1.5
= 256.25
b ) We apply law of conservation of momentum
I₁ X ω₁ = I₂ X ω₂
ω₂ = I₁ X ω₁ / I₂
Putting the values
ω₂ = 4.365 rad s⁻¹
c ) Increase in rotational kinetic energy
=1/2 I₂ X ω₂² - 1/2 I₁ X ω₁²
.5 X 256.25 X 4.365² - .5 X 356.25 X 3.14²
= 684.95 J
This energy comes from work done against the centripetal pseudo -force.
<h3><u>Answer;</u></h3>
The different atoms have different quantized energy levels
<h3><u>Explanation;</u></h3>
- The atoms of different elements have different energy levels because they have different nuclear charges and spins, and different numbers of electrons.
- Each different kind of atom, like hydrogen or radon, has a distinct nuclear charge and number of electrons. This makes the potential energy function different for each atom, and therefore results in different energy levels.
- In an emmission spectra, each bright band corresponds to a difference between energy levels within the atom.
3 hours, because for every 50 km equals one hour 150 divided into 50 equals 3
