HELP I WILL GIVE YOU BRAINLEST!

If a car passes a pedestrian, a change in pitch is __________.

enot [183]

Given two questions:

1) If a car passes a pedestrian, a change in pitch is ______________.
The answer is the change in pitch is perceived by the pedestrian since he is the one in a relatively constant position compared to the car passing.

2) In the Doppler Effect lab, which statement best describes what you demonstrated about speed and pitch?

The answer is 'speed and direction affect pitch'.

6 0

3 years ago

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A 60 and N net force is applied to a 12 kg box which is the acceleration of the box?

GarryVolchara [31]

The relation between force and mass and acceleration is

$Force = mass X acceleration$

The SI unit will be

Force = Newton

mass =kg

acceleration= $\frac{m}{s^{2} }$

thus

$acceleration = \frac{Force}{mass}$

putting values

$acceleration=\frac{60 N}{12kg}=5\frac{m}{s^{2} }$

Thus the acceleration will be

$5\frac{m}{s^{2} }$

6 0

3 years ago

Choose the isotope that would be most stable. carbon-14 barium-56 lead-82 radon-85

shutvik [7]

The most stable isotope would be lead-82.

4 0

3 years ago

The concentration of protein in a urine sample is calculated to be 2.77 μg/mL. What is the concentration of this solution in uni

maxonik [38]

Answer:

The concentration of this solution in units of pounds per gallon is $2.776*10^{-5} \frac{lb}{gal}$

Explanation:

Units of measurement are established models for measuring different quantities. The conversion of units is the transformation of a quantity, expressed in a certain unit of measure, into an equivalent one, which may or may not be of the same system of units.

In this case, the conversion of units is carried out knowing that 1 μg are equal to 2.205*10⁻⁹ Lb and 1 mL equals 0.00022 Gallons. So

$2.77 \frac{ug}{mL} = \frac{2.77 ug}{mL}$

If 1 μg equals 2.205*10⁻⁹ lb, 2.77 μg how many lb equals?

$lb=\frac{2.77ug*2.205*10^{-9}lb }{1ug}$

lb=6.10785*10⁻⁹

So, 2.77 μg= 6.10785*10⁻⁹ lb

Then:

$2.77 \frac{ug}{mL} = \frac{2.77 ug}{mL}=\frac{6.10785*10^{-9}lb }{mL} =\frac{6.10785*10^{-9}lb }{0.00022 gal} =\frac{6.10785*10^{-9}lb }{0.00022 gal}$

You get:

$2.77 \frac{ug}{mL} = 2.776*10^{-5} \frac{lb}{gal}$

The concentration of this solution in units of pounds per gallon is $2.776*10^{-5} \frac{lb}{gal}$

6 0

3 years ago

At a certain temperature, 4.0 mol NH3 is introduced into a 2.0 L container, and the NH3 partially dissociates by the reaction. 2

xxMikexx [17]

Answer:

K = 3.37

Explanation:

2 NH₃(g) → N₂(g) + 3H₂(g)

Initially we have 4 mol of ammonia, and in equilibrium we have 2 moles, so we have to think, that 2 moles have been reacted (4-2).

2 NH₃(g) → N₂(g) + 3H₂(g)

Initally 4moles - -

React 2moles 2m + 3m

Eq 2 moles 2m 3m

We had produced 2 moles of nitrogen and 3 mol of H₂ (ratio is 2:3)

The expression for K is: ( [H₂]³ . [N₂] ) / [NH₃]²

We have to divide the concentration /2L, cause we need MOLARITY to calculate K (mol/L)

K = ( (2m/2L) . (3m/2L)³ ) / (2m/2L)²

K = 27/8 / 1 → 3.37

5 0

3 years ago

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