Is time matter?<br><br>True or False<br>Plss help

I NEED HELP!!!!!!!!!!!

nadezda [96]

1. 168.1 Hz

To find the apparent frequency heard by the driver in the car, we can use the formula for the Doppler effect:

$f'=(\frac{v\pm v_o}{v\pm v_s})f$

where

f is the original sound of the horn

v is the speed of sound

$v_o$ is the velocity of the observer (the driver and the car), which is positive if the observer is moving towards the source and negative if it is moving away

$v_s$ is the velocity of the sound source (the train), which is positive if the source is moving away from the observer and negative otherwise

In this problem we have, according to the sign convention used:

$v = 343 m/s\\f = 164 Hz\\v_o = -15 m/s\\v_s = -23 m/s$

Substituting, we find:

$f'=(\frac{343-15}{343-23})(164)=168.1 Hz$

2. $2.96\cdot 10^8 m/s$

The speed of light can be calculated as

$v=\frac{d}{t}$

where

d is the distance travelled

t is the time taken

In this problem:

$d=2\cdot 3.85\cdot 10^8 =7.7\cdot 10^8 m$ is the total distance travelled by the laser beam (twice the distance between the Earth and the Moon)

t = 2.60 s is the time taken

Substituting in the formula,

$v=\frac{7.7\cdot 10^8 m}{2.60 s}=2.96\cdot 10^8 m/s$

6 0

3 years ago

A property unique to a conducting substance that determines its resistance is called:

elena-s [515]

Answer:

B. Resistivity

Explanation:

Resistance offered by a substance of unit area per unit length.

6 0

3 years ago

A(n) 10.1 g bullet is fired into a(n) 2.41 kg ballistic pendulum and becomes embedded in it. The acceleration of gravity is 9.8

fomenos

Answer:

$v = 186.90\,\frac{m}{s}$

Explanation:

The motion of ballistic pendulum is modelled by the appropriate use of the Principle of Energy Conservation:

$\frac{1}{2}\cdot (m_{p}+m_{b})\cdot v^{2} = (m_{p}+m_{b})\cdot g \cdot h$

The final velocity of the system formed by the ballistic pendulum and the bullet is:

$v = \sqrt{2\cdot g\cdot h}$

$v = \sqrt{2\cdot (9.807\,\frac{m}{s^{2}} )\cdot (0.031\,m)}$

$v\approx 0.78\,\frac{m}{s}$

Initial velocity of the bullet can be calculated from the expression derived of the Principle of Momentum:

$(0.0101\,kg)\cdot v = (2.41\,kg + 0.0101\,kg)\cdot (0.78\,\frac{m}{s} )$

$v = 186.90\,\frac{m}{s}$

5 0

3 years ago

A 20.0 cm tall object is placed 50.0 cm in front of a convex mirror with a radius of curvature of 34.0 cm. Where will the image

Neko [114]

Answer:

1.Theimage will be located at -0.13m or -13 cm

2.The height of the image will be 0.052m or 5.2cm

Explanation:

Given that;

Height of object, h=20 cm = 0.2m

Object distance in front of convex mirror, o,= 50 cm =0.5m

Radius of curvature, r, =34 cm =0.34m

Let;

Image distance, i,=?

Image height, h'=?

You know that focal length,f, is half the radius of curvature,hence

f=r/2 = 0.34/2 = 0.17m ( this length is inside the mirror, in a virtual side, thus its is negative)

f= -0.17m

Apply the relationship that involves the focal length;

$=\frac{1}{o} +\frac{1}{i} =\frac{1}{f}$

$=\frac{1}{0.5} +\frac{1}{i} =-\frac{1}{0.17}$

Re-arrange to get i

$\frac{1}{i} =-2-5.88\\\\\\\frac{1}{i} =-7.88\\\\i=-0.13m$

This is a virtual image formed at a negative distance produced through extension of drawing rays behind the mirror if you use rays to locate the image behind the mirror

Apply the magnification formula

magnification, m=height of image÷height of object

$m=\frac{h'}{h} =-\frac{i}{o}$

substitute the values to get the height of image h'

$\frac{h'}{0.20} =-\frac{-0.13}{0.5} \\\\\\h'=\frac{0.13*0.20}{0.5} \\\\\\h'=\frac{0.025}{0.5} =0.052m\\\\\\h'=5.2cm$

5 0

3 years ago

What are true statements that reflect why infants experience more fluid and electrolyte changes?

egoroff_w [7]

True statements that reflect why infants experience more fluid and electrolyte changes are that dehydration can upset the balance of electrolytes in an infant or child and the newborn is at risk of excessive water loss and hypernatremia as the result of high evaporative water loss through the skin.

As infants are not used to the environment around , they are more sensible towards problems such as Dehydration because of fast metabolism.

Dehydration can upset the balance of electrolytes in an infant or child. Children are especially vulnerable to dehydration due to their small size and fast metabolism, which causes them to replace water and electrolytes at a faster rate than adults.

Infants are particularly prone to the effects of dehydration because of their greater baseline fluid requirements (due to a higher metabolic rate), higher evaporative losses (due to a higher ratio of surface area to volume), and inability to communicate thirst or seek fluid.

The newborn is at risk of excessive water loss and hypernatremia as the result of high evaporative water loss through the skin, insensible water loss (IWL), as well as decreased capacity to concentrate the urine.

To Learn more about dehydration here

brainly.com/question/12261974?referrer=searchResults

#SPJ4

8 0

1 year ago

Is time matter?True or FalsePlss help​

Is time matter?True or FalsePlss help