Whārite mara hiko

3 ngā pātai mō ngā whārite mara hiko

1. He pōro kawe hiko, he 10 cm te whānui, he 500 μC te utu hiko. Kei te rārangi o te pokapū o te pōro ngā pūwāhi A, B, me C i te tawhiti o te 12 cm, 10 cm me te 8 cm mai i te pokapū o te pōro. Tātaihia te kaha o te mara hiko i ngā pūwāhi A, B, me C!

Kua mohiotia:

Ko te radius o te pōro kawe (R) = 10 cm = 0.1 m

Utu hiko (q) = 500 μC = 500 x 10^-6 C

r_A = 12 henimita = 0,12 mita

r_B = 10 henimita = 0,1 mita

r_C = 8 henimita = 0,08 mita

Pūmau Coulomb (k) = 9 x 10⁹

Hiahia: Te kaha o te papa hiko i te pūwāhi A (E_A), i te pūwāhi B (E_B) ā, i te pūwāhi C (E_C)

Rongoā:

a) Te kaha o te papa hiko i te pūwāhi A

E_A = kq / r_A² = (9 x 10⁹)(500 x 10^-6) / (0,12)² = (4500 x 10³) / 0,0144 = 312500 x 10³ = 3,125x10⁸ N / C

b) Te kaha o te papa hiko i te pūwāhi B

E_B = kq / r_B² = (9 x 10⁹)(500 x 10^-6) / (0,1)² = (4500 x 10³) / 0,01 = 450.000 x 10³ = 4,5x10⁸ N / C

c) Te kaha o te papa hiko i te pūwāhi C

E_C = 0 mō te noho i roto i te pōro.

2. Mēnā ka whakatakotoria he utu whakamātautau o te 4 nC ki tētahi pūwāhi, ka pāngia te utu e te kaha o te 5 × 10 – 4 N. He aha te rahi o te āpure hiko E i taua pūwāhi?

Mōhiotia:

Utu hiko whakamātautau (q) = 4 nC = 4 x 10^-9 Coulomb

Te kaha hiko (F) = 5 × 10^-4 N

Hiahia: Te rahi o te āpure hiko (E)

Rongoā:

E = F / q = (5 × 10^-4) / (4 x 10^-9) = 1,25 x 10⁵ N / C

3. E rua ngā utu q_B = 12 μC me q_C = 9 μC kei ngā pito o te tapatoru matau e ai ki te Pikitia. Tātaihia te kaha o te papa hiko i pā ki te pūwāhi A!

Mōhiotia:

Utu i te pūwāhi B (qB) = 12 μC = 12 x 10^-6 C

Utu i te pūwāhi C (qC) = 9 μC = 9 x 10^-6 C

Pūmau Coulomb (k) = 9 x 10⁹

r_AC = 4 henimita = 0,04 mita

r_AB = 3 henimita = 0,03 mita

Hiahia: te kaha o te papa hiko i te pūwāhi A

Rongoā:

E_AC = kq / r² = (9 x 10⁹)(9 x 10^-6) / (0,04)² = 81x10³ / 0,0016 = 5,0 x 10⁷ N / C

E_AB = kq / r² = (9 x 10⁹)(9 x 10^-6) / (0,03)² = 81x10³ / 0,0009 = 9,0 x 10⁷ N / C