Final answer:
The magnitude of the velocity of the second hand of an electric wall clock can be determined by multiplying the length of the hand by the angular velocity.
Step-by-step explanation:
The magnitude of the velocity of the second hand of an electric wall clock can be determined by multiplying the length of the hand by the angular velocity. The angular velocity of the second hand is 1 revolution per minute, which is equivalent to 2π radians per minute. Since the length of the hand is 15 cm, the magnitude of the velocity can be calculated as:
V = rω
V = (15 cm) * (2π radians/min) = 30π cm/min ≈ 94.25 cm/min
Therefore, the magnitude of the velocity of the second hand of the electric wall clock is approximately 94.25 cm/min.