All categories

2 years ago

What is the deceleration of a bicycle that goes from 40m/s to 20m/s in 5 seconds

Physics

1 answer:

Alex Ar [27]2 years ago

5 0

Answer:

$-4 m/s^2$

Explanation:

The acceleration of the bycicle is given by:

$a=\frac{v-u}{t}$

where

v = 20 m/s is the final velocity of the bike

u = 40 m/s is the initial velocity

t = 5 s is the time interval

Substituting numbers, we find

$a=\frac{20 m/s-40 m/s}{5s}=-4 m/s^2$

and the acceleration is negative, which means that the bycicle is slowing down.

You might be interested in

A person standing a certain distance from an airplane with four equally noisy jet engines is experiencing a sound level of 145 d

Katyanochek1 [597]

Answer:

The sound level is 138.97 dB.

Explanation:

Given that,

Sound level L= 145 dB

We need to calculate the intensity

Using formula of sound intensity

$L=10\log(\dfrac{I}{I_{0}})$

Put the value into the formula

$145=10\log(\dfrac{I}{I_{0}})$

$\log(\dfrac{I}{I_{0}})=\dfrac{145}{10}$

$\log(\dfrac{I}{I_{0}})=14.5$

$\dfrac{I}{I_{0}}=10^{14.5}$

$I=10^{14.5}\times I_{0}$

$I=10^{14.5}\times10^{-12}$

$I=316.2$

We need to calculate the noise of one engine

Using formula of intensity

$I'=\dfrac{I}{4}$

Put the value into the formula

$I'=\dfrac{316.2}{4}$

$I'=79.05$

We need to calculate the intensity level due to one engine

Using formula of sound intensity

$L'=10\log(\dfrac{I'}{I_{0}})$

$L'=10\log(\dfrac{79.05}{10^{-12}})$

$L'=138.97\ dB$

Hence, The sound level is 138.97 dB

5 0

2 years ago

Before leaving an incident assignment, you should do all of the following EXCEPT FOR:

Free_Kalibri [48]

<span>Self-dispatch to another incident</span>

7 0

2 years ago

during the course of songraphic exam, you notice lateral splaying of echoes in the far field. what can you do to improve the ima

horrorfan [7]

Answer:

lateral splaying of echoes in the far field can be improved by Increasing the maximum number of transmit focal zones and optimize their location.

8 0

2 years ago

A certain resistance thermometer read 14.5 ohms in pure melting ice and 18.5 ohms in steam at standard atmospheric pressure what

Vadim26 [7]

The resistance of the thermometer at room temperature is 15.04 ohms.

<h3 />

<h3>What is a resistance thermometer?</h3>

A resistance thermometer is a type of thermometer that measures temperature through a change in resistance.

To calculate the resistance of the thermometer at room temperature, we use the formula below.

Formula:

100/27 = 2/(x-14.5)..............Eqquation 1

Where:

x = Resistance of the thermometer at room temperature

Make x the subject of the equation

x = [(27×2)/100]+14.5
x = (54/100)+14.5
x = 0.54+14.5
x = 15.04 ohms.

Hence, The resistance of the thermometer at room temperature is 15.04 ohms.

Learn more about thermometers here: brainly.com/question/1531442

3 0

1 year ago

A spectral line from a star is observed to have a wavelength of 656.5 nm. The rest wavelength of this line is 656.8 nm. (a) What

nignag [31]

Answer:

speed of star is 1.37 × $10^{5}$ m/s

it is approaching to earth because wavelength of star is decreasing than rest

if emit same wavelength it does not move anywhere

it will remain steady condition with respect earth

Explanation:

given data

wavelength = 656.5 nm

rest wavelength = 656.8 nm

to find out

the speed of the star , is it approaching

solution

we know here equation that is

wavelength shift / wavelength at rest = velocity of source / speed of light

so put all value and find

velocity of source = 3 × $10^{-9}$ × 3 × $10^{8}$ / 656.8 × $10^{-9}$

velocity of source star = 1.37 × $10^{5}$ m/s

and

it is approaching to earth because wavelength of star is decreasing than rest

and

if emit same wavelength it does not move anywhere

it will remain steady condition with respect earth

6 0

3 years ago