interesting question.
how much fuel to hover over one place ?
The Foucault pendulum is a v v v long pendulum which can show the eart's rotation over time if the pend bob motion is tracked and recorded
Look up pulleys problem through Khan academy and a video should pop up with a problem similar and you should be able to walk through it .
Answer:
5) 13 revolutions (approximately)
Explanation:
We apply the equations of circular motion uniformly accelerated :
ωf²= ω₀² + 2α*θ Formula (1)
Where:
θ : angle that the body has rotated in a given time interval (rad)
α : angular acceleration (rad/s²)
ω₀ : initial angular speed ( rad/s)
ωf : final angular speed ( rad/s)
Data:
ω₀ = 18 rad/s
ωf = 0
α = -2 rad/s² ; (-) indicates that the wheel is slowing
Revolutions calculation that turns the wheel until it stops
We apply the formula (1)
ωf²= ω₀² + 2α*θ
0 = (18)² + 2( -2)*θ
4*θ = (18)²
θ = (18)²/4 = 81 rad
1 revolution = 2π rad
θ = 81 rad * 1 revolution / 2πrad
θ = 13 revolutions approximately
X + y = 5
x = 5 - y
2x - y = 7
2(5-y) - y = 7
10 - 2y - y = 7
10 - 3y = 7
10 - 7 = 3y
3 = 3y
y = 1
x + y = 5
x + 1 = 5
x = 5 - 1
x = 4
