Can someone please help?

To aid in the prevention of tooth decay, it is recommended that drinking water contain 0.800 ppm fluoride, F−. How many grams of

Leviafan [203]

Answer:

2.23 × 10^6 g of F- must be added to the cylindrical reservoir in order to obtain a drinking water with a concentration of 0.8ppm of F-

Explanation:

Here are the steps of how to arrive at the answer:

The volume of a cylinder = ((pi)D²/4) × H

Where D = diameter of the cylindrical reservoir = 2.02 × 10^2m

H = Height of the reservoir = 87.32m

Therefore volume of cylindrical reservoir = (3.142×202²/4)m² × 87.32m = 2798740.647m³

1ppm = 1g/m³

0.8ppm = 0.8 × 1g/m³

= 0.8g/m³

Therefore to obtain drinking water of concentration 0.8g/m³ in a reservoir of volume 2798740.647m³, F- of mass = 0.8g/m³ × 2798740.647m³ = 2.23 × 10^6 g must be added to the tank.

Thank you for reading.

4 0

3 years ago

A young parent is dragging a 65 kg (640 N) sled (this includes the mass of two kids) across some snow on flat ground, by means o

Delicious77 [7]

Answer:

b) N = 560 N, c) fr = 138.56 N, d) μ = 0.247

Explanation:

a) In the attachment we can see the free body diagram of the system

b) Let's write Newton's second law on the y-axis

N + T_y -W = 0

N = W -T_y

let's use trigonometry for tension

sin θ = T_y / T

cos θ = Tₓ / T

T_y = T sin θ

Tₓ = T cos θ

we substitute

N = W - T sin 30

we calculate

N = 640 - 160 sin 30

N = 560 N

c) as the system goes at constant speed the acceleration is zero

X axis

Tₓ - fr = 0

Tₓ = fr

we substitute and calculate

fr = 160 cos 30

fr = 138.56 N

d) the friction force has the formula

fr = μ N

μ = fr / N

we calculate

μ = 138.56 / 560

μ = 0.247

4 0

2 years ago

6. Which of these is the region of a sound wave in which the density and pressure are

Ilia_Sergeevich [38]

Answer: Compression

Explanation:

6 0

3 years ago

If a charge is located at the center of a spherical volume and the electric flux through the surface of the sphere is φ, what wo

Svetradugi [14.3K]

the correct answer is if you tripled the sphere volume, do the mat idiot

3 0

2 years ago

A metal can containing condensed mushroom soup has mass 205 g, height 11.0 cm and diameter 6.38 cm. It is placed at rest on its

AlexFokin [52]

Answer: a) 0.000093 kg.m²

b) height of the can not required

Explanation:

It is placed at rest on its side, initial velocity = 0

s = ½ a t²

3 = ½ a 1.5²

a = 2.667 m/s²

torque T = f R = μ m g R cos Φ

according to Newton's second law of rotational motion,

T = I α = I (a/R) = μ m g R cos Φ

μ = I a/(R²m g cos Φ)

∑F = m a

m g sin Φ - μ m g cos Φ = m a

canceled all m, and remember that μ = I a/(R²m g cos Φ)

g sin Φ - I a/(R²m g cos Φ) g cos Φ = a

g sin Φ - I a/(R²m) = a

9.8 sin 24° - I (2.667)/(0.0319² * 0.205) = 2.667

3.86 - I x 2.667/0.000208 = 2.667

3.86 - 12822 x I = 2.667 m

I = 3.86 - 2.667 / 12822 = 1.193 / 12822 = 0.000093 kg.m²

6 0

3 years ago