A car traveling at 26 m/s starts to decelerate steadily. It comes to a complete stop in 12 seconds. What is its acceleration?

A bungee jumper attains a speed of 30 m/s just as the bungee cord begins to stretch. If the period of stretch is 2 s while comin

Bogdan [553]

Answer: $1.53g$

Explanation:

average deceleration= ?

inial velocity: $u=0$

final velocity: $v=30m/s$

time: $t=2seconds$

The first law of kinematics :

$v=u+at$

find a the subject of the formula

$a=v-u/ t$

$a=\frac{0-30} 2$

$a=-30/2$

$a=-15m/s^{2}$

The deceleration about g(acceleration due to gravity) will be:

$15/9.8$

$1.53g$

4 0

3 years ago

A nonrelativistic electron is accelerated from rest through a potential difference. After acceleration the electron has a de Bro

aleksley [76]

Answer:

Potential difference though which the electron was accelerated is $2.67\times 10^{-6}\ uV\ .$

Explanation:

Given :

De Broglie wavelength , $\lambda=750\ nm.$

Plank's constant , $h=6.626\times 10^{-34}\ J.s \ .$

Charge of electron , $e=-1.6\times 10^{-19}\ C.$

Mass of electron , m=9.11\times 10^{-31}\ kg. $m=9.11\times 10^{-31}\ kg.$

We know , according to de broglie equation :

$\lambda=\dfrac{h}{mv}\\\\ v=\dfrac{h}{m\lambda}\\\\v=\dfrac{6.626\times 10^{-34}\ J.s \ }{9.11\times 10^{-31}\ kg\times 750\times 10^{-9}\ m }= 969.78\ m/s .$

Now , we know potential energy applied on electron will be equal to its kinetic energy .

Therefore ,

$qV=\dfrac{mv^2}{2}\\\\ V=\dfrac{mv^2}{2q}$

Putting all values in above equation we get ,

$V=2.67\times 10^{-6}\ uV .$

Hence , this is the required solution.

5 0

3 years ago

How does the nuclear charge relate to the energy of the 1s orbital?

nlexa [21]

Explanation:

Effective nuclear charge is defined as he net positive charge experienced by an electron in an atom. It is termed "effective" because the shielding effect of electrons prevents higher orbital electrons from experiencing the full nuclear charge of the nucleus due to the repelling effect of inner-layer electrons.

The 1s is the closest shell to the nucleus of an therefore maximum nuclear charge is experienced. The formula for effective nuclear charge is:

Zeff = Z – S

where

Z = the number of protons in the nucleus, and

S = the shielding constant, the average number of electrons between the nucleus and the electron.

Hence, the energy required to remove an electron from the 1s orbital is the strongest.

3 0

4 years ago

If I fell asleep at 9:42 pm and woke up at 10:06 am. What was the total hours of sleep I got?

gladu [14]

Answer:

11 hours and 24 minutes total of sleep. Nice.