The table is almost perfect. BUT ... since she called ay negative, that means she's calling the upward direction positive-y and the downward direction negative-y. In that case, since the ball moves downward from the deck to the pavement, the change in y should be negative 3.2 m. Everything else in her table is fine. Choice-D is the good one.
Now, regarding the speed of the ball ...
How long does it take to fall 3.2 m ?
Use the formula. D = 1/2 g T^2 .
3.2 = 4.9 T^2.
T^2 = 3.2/4.9
T = √(3.2/4.9) = 0.808 second.
The ball hit the pavement 0.808 second after it rolled off the deck. So that's also the time it took to move the 0.75 m horizontally.
Speed = distance / time
Speed = 0.75 m / 0.808 second
Speed = 0.928 meter/second .
Answer: It is D (The average kinetic energy of the particles)
Explanation:
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Answer:
The frequency of the piano string is either 1053 HZ or 1059 HZ.
Explanation:
Here we know that frequency of beats is equal to the difference between the frequencies between two waves .
Given that frequency of tuning fork is 1056 HZ .
Let the frequency of the piano be ' f ' .
Given that number of beats = 3.
We know that | 1056 - f | = 3 ;
⇒ 1056- f = ±3,
Upon solving this we get
f = 1056-3 and 1056 + 3
⇒ f = 1053 or 1059 .
while discovered less than 100 years ago isotopes are now used in a wide variety of scientific applications that touch the lives of almost every citizen.
Answer:
I₂ = I₀ 1/4
Explanation:
For this exercise we use the definition of intensity which is the power per unit area
I = P / A
The emitted power is constant, so
P = I A
We can write this equation for the start and end point with index 2
I₀ A₀ = I₂ A₂
I₂ = I₀ A₀ / A₂
The spot area is the area of the circle
A₀ = π r₀²
We substitute
I₂ = I₀ r₀² / r₂²
It indicates that the radius of the spot is twice the initial radius
r₂ = 2 r₀
I₂ = I₀ (r₀ / 2 r₀)²
I₂ = I₀ 1/4