All categories

2 years ago

Wind blows at the speed of 30m/s across a 175m^2 flat roof if a house.

Physics

1 answer:

Makovka662 [10]2 years ago

8 0

Answer:

the net force is 101587.5 N

Explanation:

The speed of wind

v = 30 m/s

The area of roof,

A = 175 m 2

The expression for the Bernoulli's theorem.

P = 12 ρv 2 ...... (1)

Here,

P is the pressure difference,

ρ is the density of air and

v is the speed of wind.

The expression for the pressure.

P = F A ..... (2)

Here,

F is the force and

A is the area of roof.

Part (a)

Substitute the values for the pressure difference in equation (1)

P = 12 × 1.29 × (30) 2 P = 580.5 Pa

Thus, the pressure difference at the roof between the inside and outside air is

580.5 Pa

Part (b)

Substitute the values for the net force in equation (2)

580.5 = F 175 F = 101587.5 N

Thus, the net force is 101587.5 N.

You might be interested in

The diagram shows a heat engine. In which area of the diagram is unusable thermal energy detected?

Marat540 [252]

Nope, I disagree with the former answer. The answer is definitely Z. <u>W area</u> (boxed with red outline) is represented as the hot reservoir while <u>Z area</u> is the cold reservoir (boxed with blue outline). X area is the heat engine itself and Y area is the work produced from thermal energy from hot reservoir. Typically, all heat engines lose some heat to the environment (based from the second law of thermodynamics) that is symbolically illustrated by the lost energy in the cold reservoir. This lost thermal energy is basically the unusable thermal energy. The higher thermal energy lost, the less efficient your heat engine is.

7 0

2 years ago

Read 2 more answers

A closely wound rectangular coil of 80 turns has dimensions 25.0 \rm cm by 40.0 \rm cm. The plane of the coil is rotated from a

Pepsi [2]

Answer:

88.3

Explanation:

Emf in a rotating coil is given by rate of change of flux:

E= dФ/dt=(NABcos∅)/ dt

N: number of turns in the coil= 80

A: area of the coil= 0.25×0.40= 0.1

B: magnetic field strength= 1.1

Ф: angle of rotation= 90- 37= 53

dt= 0.06s

E= (80 × 0.4× 0.25×1.10 × cos53)/0.06= 88.3V

4 0

2 years ago

Read 2 more answers

A ball with a mass of 0.5 kilograms is lifted to a height of 2.0 meters and dropped. It bounces back to a height of 1.8 meters.

Degger [83]

Hi, thank you for posting your question here at Brainly.

To compute for the change in potential energy, the equation would be:

delta PE = mg*delta h
delta PE = 0.5*9.81*(2-1.8)
delta Pe = 0.98 J

The potential energy is converted to kinetic energy.

3 0

2 years ago

Read 2 more answers

A bird is flying to the right when a gust of wind causes the bird to accelerate leftward at 0.5\,\dfrac{\text m}{\text s^2}0.5 s

Licemer1 [7]

The initial velocity of the bird before the gust of wind : <u>4 m/s</u>

<h3>Further explanation</h3>

An equation of uniformly accelerated motion

$\large {\boxed {\bold {x = xo + vo.t + \frac {1} {2} at ^ 2}}}$

v = vo + at

Vt² = vo² + 2a (x-xo)

x = distance on t

vo/vi = initial speed

vt/vf = speed on t /final speed

a = acceleration

Acceleration is a change in speed within a certain time interval

a = Δv /Δ t

$\displaystyle a=\frac{v2-v1}{t2-t1}$

Let complete the task :

A bird is flying to the right when a gust of wind causes the bird to accelerate leftward at 0.5 m/s² for 3 s. After the wind stops, the bird is flying to the right with a velocity of 2.5 m/s.

Assuming the acceleration from the wind is constant, what was the initial velocity of the bird before the gust of wind?

we can use formula :

vf = vi + a.t

vf = final velocity = 2.5 m/s

vi = asked

a = - 0.5 m/s²(leftward=negative)

t = 3 s

then :

$\displaystyle 2.5=vi-0.5.3\\\\vi=2.5+1.5\\\\vi=\boxed{\bold{4\frac{m}{s}}}$