Answer:
Explanation:
Given that,
Surface area A= 17m²
The speed at the top v" = 66m/s
Speed beneath is v' =40 m/s
The density of air p =1.29kg/m³
Weight of plane?
Assuming that,
the height difference between the top and bottom of the wind is negligible and we can ignore any change in gravitational potential energy of the fluid.
Using Bernoulli equation
P'+ ½pv'²+ pgh' = P'' + ½pv''² + pgh''
Where
P' is pressure at the bottom in N/m²
P" is pressure at the top in N/m²
v' is velocity at the bottom in m/s
v" is velocity at the top in m/s
Then, Bernoulli equation becomes
P'+ ½pv'² = P'' + ½pv''²
Rearranging
P' — P'' = ½pv"² —½pv'²
P'—P" = ½p ( v"² —v'²)
P'—P" = ½ × 1.29 × (66²-40²)
P'—P" = 1777.62 N/m²
Lift force can be found from
Pressure = force/Area
Force = ∆P ×A
Force = (P' —P")×A
Since we already have (P'—P")
Then, F=W = (P' —P")×A
W = 1777.62 × 17
W = 30,219.54 N
The weight of the plane is 30.22 KN
I believe the answer is c but I’m not 100% sure
Answer is Global Warming causes destruction of our ecosystem due to increased temperatures, drought, fire, weed and pest infestations, more intense storms, water shortages, melting ice caps and glaciers, air pollution.
In this item, we let x be the rate of the boat in still water and y be the rate of the current.
Upstream. When the boat is going upstream, the speed in still water is deducted by the speed of the current because the boat goes against the water. The distance covered is calculated by multiplying the number of hours and the speed.
(x - y)(3) = 144
Downstream. The speed of the boat going downstream is equal to x + y because the boat goes with the current.
(x + y)(2) = 144
The system of linear equations we can use to solve for x is,
3x - 3y = 144
2x + 2y = 144
We use either elimination or substitution.
We solve for the y of the first equation in terms of x,
y = -(144 - 3x)/3
Substitute this to the second equation,
2x + 2(-1)(144 - 3x)/3 = 144
The value of x from the equation is 60
<em>ANSWER: 60 km/h</em>
Explanation:
Average speed = distance / time
|v| = (7 km + 2 km) / (2 hr + 1 hr)
|v| = 3 km/hr
Average velocity = displacement / time
v = (7 km east + 2 km east) / (2 hr + 1 hr)
v = 3 km/hr east
