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3 years ago

Find the wavelength of a 26 Hz sound wave traveling through air at 20ºC. Hint: speed of sound at 20ºC = 343 m/s

1 answer:

3 0

The correct answer for the question that is being presented above is this one: "B. 13m."

The formula of wave velocity is this:
wave velocity = f * <span>λ
</span>λ = v / f
<span>λ</span> = 343m/s / 26Hz
λ = 13.20m .. ans (b)

Here are the following choices:
A. 5m
B. 13m
C. 28m
D. 58m

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Two technicians are discussing a problem where the brake pedal travels too far before the vehicle starts to slow. Technician A s

iVinArrow [24]

Answer:

Technician A

Explanation:

If Technician B was correct, and the master cylinder is defective - then no braking action would occur.

This is not true however, as some breaking action eventually occurs, meaning it must be out of adjustment.

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4 years ago

What is the direction of the magnetic field if an electron moving in the positive x direction experiences a magnetic force in th

Alex787 [66]

Given :

An electron moving in the positive x direction experiences a magnetic force in the positive z direction.

To Find :

The direction of the magnetic field.

Solution :

We know, force is given by :

$\vec{F}=q(\vec{v}\times \vec{B)}$

Here, q = -e.

$\vec{F}=(-e)(\vec{v}\times \vec{B)}\\\\\hat{k}=(-e)(\hat{i}\times \vec{B})$

Now, for above condition to satisfy :

$\hat{i}\times \vec{B}=-\hat{k}$

So, $\vec{B}=-\hat{j}$

Therefore, direction of magnetic field is negative y direction.

Hence, this is the required solution.

7 0

3 years ago

The largest watermelon ever grown had a mass of 118 kg. Suppose this watermelon were exhibited on a platform 5.00 m above the gr

WINSTONCH [101]

Answer: height = 3.98m

Explanation: by placing the watermelon at a height above the ground, it has a potential energy of the formulae

p = mgh

p = potential energy = 4.61kJ = 4610J

m = mass of watermelon = 118 kg

g = acceleration due gravity = 9.8 m/s²

4610 = 118 * 9.8 * h

h = 4610/ 118 * 9.8

h = 4610/ 1156.4

h = 3.98m

6 0

3 years ago

A particle having a speed of 0.87c has a momentum of 10-16 kg·m/s. what is its mass?

cupoosta [38]

The momentum p of a moving particle is the product between its mass, m, and tis velocity, v:
$p=mv$
In our problem, we know $p=10^{-16}~Kg \cdot m/s$ and $v=0.87c=0.87\cdot 3\cdot10^8~m/s=2.61\cdot 10^8~m/s$ , and using the relationship mentioned above, we can find the mass m of the particle:
$m= \frac{p}{v} =3.8\cdot10^{-25}~Kg$

8 0

3 years ago

Which of the following would illustrate a quadratic relation between the dependent and independent variables when graphed?

Kitty [74]

Answer: option A. a graph of the area of a circle vs. its radius r (A = πr²).

Explanation:

A quadratic relation between the dependent and independent variables shows the independent variable raised to the power of 2.

This is it is a polynomial with general form ax² + bx + c, whewre a, b, and c, named coeficients, are constants.

The function is y = ax² + bx + c, where x is the independent variable and y is the dependent variable.

As stated in the question, the area of a circle is given by A = πr².

In this case, A is the dependent variable and r is the independent variable.

π is assumed as the coefficient of the quadratic term, and the other coefficients are assumed 0, since there are no either terms on r or constants.

The equation a = 1/b is an inverse relation, not a quadratic relation.

The relation of distance vs. time for a car moving at constant speed is a linear relation of the kind v = u + st.

The mass of water vs. the volume of water in a drinking glass is a direct relation, mass = density × volume

Therefore, the only quadratic relation is shown by a graph of the area of a circle vs. its radius r.

3 0

3 years ago