Answer:
The reason for phonograph installation is to provide information about humans to interstellar aliens.
Explanation:
Phonographs are archaic forms of gramophone which are able to record and reproduce sound.Phonographs were used in early days in voyagers to help transmit information about humans to nearby alien species in space.
Answer:
22kj
Explanation:
set h = 0 at the end of slide.
final height is -12m
initial condition will be Ui = 0
Ki = 1/2mv² = 1/2 x 61 x (27)² = 22234.5J
Final condition is Ui = mgh = 61 x 9.8 x -12 = -7173J
Ki = 1/2mv²
Ki= 1/2 x 61 x (16)² = 7808J
conservation energy says that
Ui + Ki = Uf +Kf +ΔEth
so ΔEth = Ui + Ki - Uf - Kf
ΔEth = 22234.5 - 7808 + 7173
ΔEth = 21600J
ΔEth =22Kj
There are mistakes in the question as the unit of speed and height is not mention here.The correct question is here
A student standing on the ground throws a ball straight up. The ball leaves the student's hand with a speed of 16.0m/s when the hand is 1.80m above the ground.How long is the ball in the air before it hits the ground? (The student moves her hand out of the way.)
Answer:
t=3.37s
Explanation:
Given Data
As we have taken hand at origin and positive upward
So given data are

To find
time taken by the ball before it hits the ground
Solution
By using the common kinematic equation

Put the given values and find for t
So

Apply quadratic formula to solve for t