Let h = the distance from the edge of the wall to the water surface (m).
Use g = 9.8 m/s² and neglect air resistance.
The initial vertical velocity of the pebble is zero.
Because the pebble hits the surface of the water after 1.5 s, therefore
h = (1/2)*(9.8 m/s²)*(1.5 s)² = 11.025 m
Answer: 11.025 m
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:
4/10 of L.
Explanation:
A stopped pipe is a pipe with one closed end and one opened end. it is also called a closed pipe.
The fundamental mode of a stopped pipe is also called its fundamental frequency, and is f₁=v/4L.
Where f₁=fundamental frequency, v= velocity of sound, L= Length of pipe.
The fifth harmonic of the stopped pipe f₅ =5v/4L .................(1)
For an open pipe,
Fundamental mode is also called fundamental frequency f₁₀=v/2l₀ .......... (2)
Where f₁₀ = fundamental frequency of a closed pipe, v= velocity of sound and l₀=length of the resulting open pipe.
from the question, the fundamental mode of the resulting open pipe = The fifth harmonic of the original stopped pipe.
∴ f₅=f₁₀
⇒5v/4L = v/2l₀
Equating v from both side of the equation,
⇒ 5/4L = 1/2l₀
Cross multiplying the equation,
5×2l₀ = 4L× 1
10l₀ = 4L
Dividing both side of the equation by the coefficient of l₀ i.e 10
10l₀/10 = 4L/10
∴ l₀ = 4/10(L)
∴ 4/10 of L must be cut off
Answer:
Explanation:
Given
time taken to complete the circle=7.9 s
radius of circle(r)=15 m
velocity of rider is given by 
Let us suppose T is the tension in the chain and 
is the angle which chain makes with vertical
Therefore 
--2
Divide 1 & 2 we get
Answer:
Decreased by a factor of 4.5
Explanation:
"We have Newton formula for attraction force between 2 objects with mass and a distance between them:
where 
is the gravitational constant on Earth. 
are the masses of the object and Earth itself. and R distance between, or the Earth radius.
So when R is tripled and mass is doubled, we have the following ratio of the new gravity over the old ones:
Since 
and 
So gravity would have been decreased by a factor of 4.5
