Answer:
(a) 110 rev/ min
(b) 5/6
Explanation:
As per the conservation of linear momentum,
L ( initial ) = L ( final )
I' ω' = ( I' + I'' ) ωf
I' is the rotational inertia of first wheel and I'' is the rotational inertia of second wheel which is at rest.
(a)
So, ωf = I' ω' / ( I' + I'' )
As I'' = 5I'
ωf = I' ω' / ( I' + 5I' )
ωf = ω'/ 6
now we know ω' = 660 rev / min
therefore ωf = 660/6
= 110 rev/ min
(b)
Initial kinetic energy will be K'
K' = I'ω'² / 2
and final K.E. will be K'' = ( I' + I'' )ωf² / 2
K'' = ( I' + 5I' ) (ω'/ 6)²/ 2
K'' = 6I' ω'²/72
K'' = I' ω'²/ 12
therefore the fraction lost is
ΔK/K' = ( K' - K'' ) / K'
= {( I'ω'² / 2) - (I' ω'²/ 12)} / ( I'ω'² / 2)
= 5/6
Answer:
B.It is a satellite that collects data about rain and snow
C.Its orbit covers 90 percent of Earth’s surface
F.The sensors measure microwaves
The sun <u><em>appears</em></u> brighter than any other star.
(It isn't really, but it looks that way because it's much much much much much much closer to us than any other star.)
Answer:
8 seconds
Explanation:
From Newton's second law;
Ft = m(v-u)
F = Force applied
t = time taken
v = final velocity
u = initial velocity
20 * t = 32 (9 - 4)
20t = 32 * 5
t = 32 * 5/ 20
t = 8 seconds
