A static charge that is produced by a nearby objet is an?

A rigid dam is composed of material of SG = 5 . The dam height is 20 m . What is the minimum thickness b of the dam necessary to

Kay [80]

Answer:

b = 5.164 m is the minimum thickness of the dam

Explanation:

Given

SG = 5

h = 20 m

b = ?

w = 1 m

γw = 9800 N/m³

We can get the forces as follows

Fp = γw*(h/2)*(h*w)

⇒ Fp = (9800 N/m³)*(20 m/2)*(20 m*1 m) = 1.96*10⁶N

W = (SG*γw)*(h*b*w)

⇒ W = (5*9800 N/m³)*(20 m*b*1 m) = (9.8*10⁵N/m)*b

Then, we apply

∑M₀ = 0 (counterclockwise)

- Fp*(h/3) + W*(b/2) = 0

⇒ - 1.96*10⁶N*(20 m/3) + (9.8*10⁵N/m)*b*(b/2) = 0

- 13.066*10⁶N-m + (4.9*10⁵N/m)*b² = 0

⇒ b = 5.164 m is the minimum thickness of the dam

3 0

3 years ago

The surface tension of water was determined in a laboratory by using the drop weight method. 100 drops were released from a bure

Lapatulllka [165]

Answer:

γ = 0.06563 N / m

9.78% difference

Explanation:

Solution:-

- Surface tension is the ability of any fluid to resist any external force which causes a decreases in surface area of the impact area due to inward compressive forces. These compressive forces occur due to cohesive nature of the fluid molecules.

- Mathematically, surface tension ( γ ) is defined as the force felt per unit length by the fluid.

γ = F / L

Where,

F: Force imparted

L: The length over which force is felt

- We are given the mass ( M ) of ( n = 100 ) water droplets to e 3.78 g. The mass of a single droplet ( m ) can be evaluated as follows:

m = M / n

m = 3.78 / 100

m = 0.0378 g

- The force ( F ) imparted by a single drop of water from the burette can be determined from the force balance on a single droplet. Assuming the distance over which the drop falls is negligible and resistive forces are negligible. Then the only force acting on the droplet is due to gravity:

F = m*g

F = 0.0378*9.81*10^-3

F = 0.000370818 N

- The length over which the force is felt can be magnified into a circular area with diameter equal to that of a single droplet ( d ). The circumferential length ( L ) of the droplet would be as follows:

L = π*d

L = π*( 0.0018 )

L = 0.00565 m

- Then the surface tension would be:

γ = F / L

γ = 0.000370818 / 0.00565

γ = 0.06563 N / m

- The tabulated value of water's surface tension is given as follows:

γa = 0.07275 N/m

- We will determine the percentage difference between the value evaluated and tabulated value as follows:

$p.diff = \frac{gamma_a - gamma}{gamma_a} * 100\\\\p.diff = \frac{0.07275- 0.06563}{0.07275} * 100 \\\\p.diff = 9.78 %$

- The %difference between is within the allowable practical limits of 10%. Hence, the evaluated value ( γ = 0.06563 N / m ) can be accepted with 9.78% error.

8 0

3 years ago

The fall of a body on the earth surface cannot be a complete free fall ? why<br>

anzhelika [568]

It can never be in a total free fall due to air resistance and terminal velocity due to mass

8 0

2 years ago

A parallel-plate vacuum capacitor has 8.38 J of energy stored in it. The separation between the plates is 2.30 mm. If the separa

Elanso [62]

Answer:

Explanation:

plate separation = 2.3 x 10⁻³ m