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.
Answer:

Explanation:
Given that initially ball moves in the horizontal direction ,it means that the velocity in the vertical direction is zero.
Horizontal distance = 13 m
Vertical distance = 57 cm
Lets take time to cover 57 cm distance in vertical direction is t.
We know that g is the constant acceleration in the vertical direction so we can apply the equation of motion in the vertical direction.

Here 
S= 57 cm

t=0.34 s
Now in the horizontal direction

Here x=13 m
t= 0.34 s
So


So the initial speed of ball is 38.13 m/s.
To solve this problem it is necessary to apply the concepts related to the heat flux rate expressed in energetic terms. The rate of heat flow is the amount of heat that is transferred per unit of time in some material. Mathematically it can be expressed as:

Where
k = 0.84 J/s⋅m⋅°C (The thermal conductivity of the material)
Area
Length
= Temperature of the "hot"reservoir
= Temperature of the "cold"reservoir
Replacing with our values we have that,



Therefore the correct answer is B.
Answer:
She passes through a loud spot at x = 19.5m from the first speaker. Constructive interference occurs here.
At the quiet spot destructive interference occurs. The minimum distance for this to occur is 20.25 from the first speaker.
Explanation: