Answer:
U = 2,195 10⁵ J
Explanation:
The potential energy is
U = m g and
in this case each person has a mass of 75 kg and the elevator has a mass of 500 kg, the total mass is
m_total = m_elevator + 4 m_person
m_total = 500 + 4 75
m_toal = 800 kg
let's calculate
U = 800 9.8 28
U = 2,195 10⁵ J
Is going to the west, because momentum is mass in motion so its motion is going to the direction of the netforce. Hope it helps
'H' = height at any time
'T' = time after both actions
'G' = acceleration of gravity
'S' = speed at the beginning of time
Let's call 'up' the positive direction.
Let's assume that the tossed stone is tossed from the ground, not from the tower.
For the stone dropped from the 50m tower:
H = +50 - (1/2) G T²
For the stone tossed upward from the ground:
H = +20T - (1/2) G T²
When the stones' paths cross, their <em>H</em>eights are equal.
50 - (1/2) G T² = 20T - (1/2) G T²
Wow ! Look at that ! Add (1/2) G T² to each side of that equation,
and all we have left is:
50 = 20T Isn't that incredible ? ! ?
Divide each side by 20 :
<u>2.5 = T</u>
The stones meet in the air 2.5 seconds after the drop/toss.
I want to see something:
What is their height, and what is the tossed stone doing, when they meet ?
Their height is +50 - (1/2) G T² = 19.375 meters
The speed of the tossed stone is +20 - (1/2) G T = +7.75 m/s ... still moving up.
I wanted to see whether the tossed stone had reached the peak of the toss,
and was falling when the dropped stone overtook it. The answer is no ... the
dropped stone was still moving up at 7.75 m/s when it met the dropped one.
Given Information:
frequency = 1240 Hz
width = a = 1.13 m
speed of sound = c = 344 m/s
Required Information:
angle = θ = ?
Answer:
θ = 14.18 rad
Explanation:
We can find out the angle relative to the centerline perpendicular to the doorway by using the following relation
sin(θ) = λ/a
Where λ is the wavelength of the sound wave and a is width
λ = c/f
Where c is the speed of the sound and f is the frequency
λ = 344/1240
λ = 0.277
sin(θ) = λ/a
θ =sin⁻¹(λ/a)
θ =sin⁻¹(0.277/1.13)
θ =sin⁻¹(0.277/1.13)
θ = 14.18 rad