Question

When a piece of polythene is rubbed with wool, a charge of −2×10⁻⁷C is developed on polythene. What mass is transferred to polythene?

A. 5.69×10⁻¹⁹kg
B. 2.25×10⁻¹⁹kg
C. 9.63×10⁻¹⁹kg
D. 11.38×10⁻¹⁹kg

Answer 1

The correct answer is (D) 11.38x10^-19 kg.

When a piece of polythene is rubbed with wool, a charge of -2x10^-7C is developed on the polythene. To find the mass transferred to the polythene, we can use the equation Q = ne. Rearranging the equation and plugging in the values, we find that the mass transferred to the polythene is approximately 1.14x10^-18 kg.

Step-by-step explanation:

When a piece of polythene is rubbed with wool, electrons are transferred from the wool to the polythene, resulting in a negative charge on the polythene.

The charge developed on the polythene is -2x10^-7 C. To find the mass transferred to the polythene, we can use the equation Q = ne, where Q is the charge, n is the number of electrons transferred, and e is the charge of one electron, which is -1.6x10^-19 C.

Rearranging the equation, we have n = Q/e.

Plugging in the values, we get n = -2x10^-7 C / -1.6x10^-19 C

= 1.25x10^12 electrons.

The mass transferred can be calculated using the equation m = n x me, where n is the number of electrons transferred and me is the mass of one electron, which is 9.109x10^-31 kg.

Plugging in the values, we get m = 1.25x10^12 x 9.109x10^-31 kg = 1.1386x10^-18 kg.

Rounding to the appropriate significant figures, the mass transferred to the polythene is approximately 1.14x10^-18 kg. Therefore, the correct answer is (D) 11.38x10^-19 kg.