Jika cahaya dengan panjang gelombang 4.500 Å jatuh...

Jika cahaya dengan panjang gelombang 4.500 Å jatuh pada sebuah permukaan, didapatkan bahwa potensial henti elektron-elektron yang dipancarkan ini 0,75 V. Berapakah potensial henti elektron foto jika cahaya dengan panjang gelombang 3.000 Å jatuh pada permukaan tersebut? $undefined$

Jawaban:

$begin mathsize 14px style lambda subscript 1 equals 4.500 space straight Å equals 4 comma 5 cross times 10 to the power of negative 7 end exponent space straight m V subscript s 1 end subscript equals 0 comma 75 space straight V lambda subscript 2 equals 3.000 space straight Å equals 3 cross times 10 to the power of negative 7 end exponent space straight m end style$

Ditanyakan: $begin mathsize 14px style V subscript s 2 end subscript equals ? end style$
Jawab:

$begin mathsize 14px style E k equals q. V subscript s 1 end subscript E k subscript 1 equals open parentheses 1 comma 6 cross times 10 to the power of negative 19 end exponent close parentheses open parentheses 0 comma 75 close parentheses E k subscript 1 equals 1 comma 2 cross times 10 to the power of negative 19 end exponent space straight J end style$

Maka fungsi kerja logam
$begin mathsize 14px style E k subscript 1 equals h c over lambda minus W subscript 0 1 comma 2 cross times 10 to the power of negative 19 end exponent equals open parentheses 6 comma 63 cross times 10 to the power of negative 34 end exponent close parentheses fraction numerator open parentheses 3 cross times 10 to the power of 8 close parentheses over denominator open parentheses 4 comma 5 cross times 10 to the power of negative 7 end exponent close parentheses end fraction minus W subscript 0 1 comma 2 cross times 10 to the power of negative 19 end exponent equals 4 comma 42 cross times 10 to the power of negative 19 end exponent minus W subscript 0 W subscript 0 equals 3 comma 22 cross times 10 to the power of negative 19 end exponent space straight J end style$

Sehingga potensial henti untuk panjang gelombang kedua
$begin mathsize 14px style V subscript s 2 end subscript equals fraction numerator E k subscript 2 over denominator q end fraction V subscript s 2 end subscript equals fraction numerator E subscript 2 minus W subscript 0 over denominator q end fraction V subscript s 2 end subscript equals fraction numerator h begin display style c over lambda subscript 2 end style minus W subscript 0 over denominator q end fraction V subscript s 2 end subscript equals fraction numerator open parentheses 6 comma 63 cross times 10 to the power of negative 34 end exponent close parentheses begin display style fraction numerator open parentheses 3 cross times 10 to the power of 8 close parentheses over denominator open parentheses 3 cross times 10 to the power of negative 7 end exponent close parentheses end fraction end style minus open parentheses 3 comma 22 cross times 10 to the power of negative 19 end exponent close parentheses over denominator 1 comma 6 cross times 10 to the power of negative 19 end exponent end fraction V subscript s 2 end subscript equals fraction numerator 3 comma 41 cross times 10 to the power of negative 19 end exponent over denominator 1 comma 6 cross times 10 to the power of negative 19 end exponent end fraction V subscript s 2 end subscript equals 2 comma 13 space straight V end style$

Jadi, potensial henti ketika panjang gelombang 3.000 Å adalah 2,13 V.

Ruangguru

RUANGGURU HQ

Jl. Dr. Saharjo No.161, Manggarai Selatan, Tebet, Kota Jakarta Selatan, Daerah Khusus Ibukota Jakarta 12860

Coba GRATIS Aplikasi Ruangguru

Download di Google Play

Download di Appstore

Produk Ruangguru

Produk Lainnya

Bantuan & Panduan

Hubungi Kami

081578200000

[email protected]

02140008000

Ikuti Kami

Instagram

Facebook

Twitter

Youtube