Answer:
<em>The kinetic energy of a spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>
<em></em>
Explanation:
Let us first consider the initial characteristics of the angular motion of the disk
moment of inertia = 
angular speed = ω
For the second case, we consider the characteristics to now be
moment of inertia =
(five times larger)
angular speed = ω/5 (five times smaller)
Recall that the kinetic energy of a spinning body is given as

therefore,
for the first case, the K.E. is given as

and for the second case, the K.E. is given as


<em>this is one-tenth the kinetic energy before its spinning characteristics were changed.</em>
<em>This implies that the kinetic energy of the spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>
Wave D has the same wavelength as wave A, but the amplitude is lower. The answer is Wave D.
Answer:
She is going at 30.4 m/s at the top of the 35-meter hill.
Explanation:
We can find the velocity of the skier by energy conservation:

On the top of the hill 1 (h₁), she has only potential energy since she starts from rest. Now, on the top of the hill 2 (h₂), she has potential energy and kinetic energy.
(1)
Where:
m: is the mass of the skier
h₁: is the height 1 = 82 m
h₂: is the height 2 = 35 m
g: is the acceleration due to gravity = 9.81 m/s²
v₂: is the speed of the skier at the top of h₂ =?
Now, by solving equation (1) for v₂ we have:
Therefore, she is going at 30.4 m/s at the top of the 35-meter hill.
I hope it helps you!
Answer:
a) v2=4147.72 m/s
b) stotal=5.53x10^6 m
Explanation:
a) the length from the center of the earth is equal to:
L1=1x10^6+((6.37/2)x10^6)=4.18x10^6 m
the velocity is 5.14 km/s=5.14x10^3 m/s
the farthest distance is equal to:
L2=2x10^6+((6.37/2)x10^6)=5.18x10^6 m
As the angular momentum is conserved, we have to:
I1=I2
m*L1*v1=m*L2*V2, where m is the mass of satelite
clearing v2:
v2=(L1*V1)/L2=(4.18x10^6*5.14x10^3)/5.18x10^6=4147.72 m/s
b) Using the Newton 3rd law:
vf^2=vi^2+2as
where:
a=g=9.8 m/s^2
vf=0
vi=5.14 km/s
s=?
Clearing s:
s=(vf^2-vi^2)/(2g)=((0-(5.14x10^3)^2)/(2*9.8)=1.35x10^6 m
the total distance is equal to:
stotal=s+L1=1.35x10^6+4.18x10^6=5.53x10^6 m