Which of the following best describes a longitudinal wave?

After fixing a flat tire on a bicycle you give the wheel a spin. Its initial angular speed was 5.40 rad/s and it rotated 12.3 re

zaharov [31]

To solve this problem it is necessary to apply the concepts related to the kinematic equations of angular motion.

By definition, acceleration can be expressed as the change in angular velocity squared over a given period of distance traveled.

$\alpha = \frac{\omega^2}{2\theta}$

where,

$\omega =$ Angular velocity

$\theta =$ Angular displacement.

In turn, as a function of time, we can represent it as,

$\alpha = \frac{\omega}{t}$

For our case we have to,

$\omega = 5.4rad/s$

$\theta = 12.3rev = 12.3rev(\frac{2\pi rad}{1rev})=24.6\pi rad$

PART A) In the case of angular acceleration we have to,

$\alpha = \frac{\omega^2}{2\theta}$

$\alpha = \frac{(5.4)^2}{2*24.6\pi}$

$\alpha = 0.1886rad/s^2$

PART B) Through the definition of angular acceleration as a function of time we can calculate it,

$\alpha = \frac{\omega}{t}$

$t = \frac{\omega}{\alpha}$

$t = \frac{5.4}{0.1886}$

$t = 28.63s$

3 0

4 years ago

Carmen is heating some water and trying to measure the temperature of water using a Celsius thermometer. Which measurement can s

andrew-mc [135]

100° C she can expect once the water begins to boil.

Option: B

Explanation:

The boiling point for water at 1 pressure atmosphere of sea level is 212 ° F or 100 ° C. That value isn't a fixed. Water's boiling point is dependent on the ambient pressure, which varies based on elevation. At a lower temperature, water boils as one gains altitude like getting higher on a hill, and boils at a higher temperature if one increases the atmospheric pressure of returning to or below sea level.

It also relies upon the water's purity. Water containing contaminants like salted water boils at a level higher than pure water. This effect is called acceleration of the boiling point and is one of the material's colligative features.

4 0

3 years ago

Read 2 more answers

(a) If the coefficient of kinetic friction between tires and dry pavement is 0.80, what is the shortest distance in which you ca

Colt1911 [192]

a) 52.5 m

b) 16.0 m/s

Explanation:

a)

The motion of a car slowed down by friction is a uniformly accelerated motion, so we can use the following suvat equation:

$v^2-u^2=2as$

where

v = 0 is the final velocity (the car comes to a stop)

u = 28.7 m/s is the initial velocity of the car

a is the acceleration

s is the stopping distance

For a car acted upon the force of friction, the acceleration is given by the ratio between the force of friction and the mass of the car, so:

$a=\frac{-\mu mg}{m}=-\mu g$

where:

$\mu=0.80$ is the coefficient of friction

$g=9.8 m/s^2$ is the acceleration due to gravity

Substituting and solving for s, we find:

$s=\frac{v^2-u^2}{-2\mu g}=\frac{0-(28.7)^2}{-2(0.80)(9.8)}=52.5 m$

b)

In this case, the car is moving on a wet road. Therefore, the coefficient of kinetic friction is

$\mu=0.25$

Here we want the stopping distance of the car to remain the same as part a), so

$s=52.5 m$

We can use again the same suvat equation:

$v^2-u^2=2as$

And since the final velocity is zero

u = 0

We can find the initial velocity of the car:

$v=\sqrt{2as}=\sqrt{2\mu gs}=\sqrt{2(0.25)(9.8)(52.5)}=16.0 m/s$

7 0

3 years ago

Do electric fields point towards or away from positive charges?

juin [17]

Answer:

it points towards positive charges

3 0

3 years ago

The magnetic lines of force always travel from north to south true or false

kumpel [21]

Answer:

True

Explanation:

Magnetic field lines outside of a permanent magnet always run from the north magnetic pole to the south magnetic pole. Therefore, the magnetic field lines of the earth run from the southern geographic hemisphere towards the northern geographic hemisphere.

7 0

2 years ago