Explanation:
Initial energy = final energy + work done by friction
PE = PE + KE + W
mgH = mgh + 1/2 mv² + W
(800)(9.8)(30) = (800)(9.8)(2) + 1/2 (800) v² + 25000
v = 22.1 m/s
Without friction:
PE = PE + KE
mgH = mgh + 1/2 mv²
(800)(9.8)(30) = (800)(9.8)(2) + 1/2 (800) v²
v = 23.4 m/s
Answer:
The observed wavelength on Earth from that hydrogen atom is
.
Explanation:
Given that,
The actual wavelength of the hydrogen atom, 
A hydrogen atom in a galaxy moving with a speed of, 
We need to find the observed wavelength on Earth from that hydrogen atom. The speed of galaxy is given by :

is the observed wavelength

So, the observed wavelength on Earth from that hydrogen atom is
. Hence, this is the required solution.
Answer:
The velocity of the Mr. miles is 17.14 m/s.
Explanation:
It is given that,
Mr. Miles zips down a water-slide starting at 15 m vertical distance up the scaffolding, h = 15 m
We need to find the velocity of the Mr. Miles at the bottom of the slide. It is a case of conservation of energy which states that the total energy of the system remains conserved. Let v is the velocity of the Mr. miles. So,

g is the acceleration due to gravity

v = 17.14 m/s
So, the velocity of the Mr. miles is 17.14 m/s. Hence, this is the required solution.
The velocities and the speed build a triangle, where the 1.7 m/s are the hypotenuse and the x-velocity and y-velocity are the other sides.
<span>So the x-velocity is: speed*cos(angle) </span>
<span>now plug in </span>
<span>x=1.7 m/s * cos(18.5)=1.597 m/s </span>
Matter, substance. Material howya call it.