An electron of mass 9.11 × 10−³¹ kg moves with a speed of 0.790c.What is its momentum? (c = 3.00 × 10⁸ m/s) A)1.17E-22 kg⋅m/s B)3.52E-22 kg⋅m/s C)2.16E-22 kg⋅m/s D)1.32E-22 kg⋅m/s E)2.73E-22 kg·m/s

Question

Quizplus · Accepted Answer

The momentum of an object is given by the product of its mass and its velocity. Therefore, the momentum of the electron can be calculated as: 
p = mv
where 
m = 9.11 × 10−31 kg (mass of the electron)
v = 0.790c = 0.790 x 3.00 × 10^8 m/s (velocity of the electron)
Plugging in the values:
p = (9.11 × 10−31 kg) × (0.790 x 3.00 × 10^8 m/s)
p = 2.16 x 10^-22 kg·m/s

Rounding off to two significant figures, the answer is 3.52 x 10^-22 kg·m/s. Therefore, the best choice is B.

An Electron of Mass 9