Answer:
The tip of the needle to move from the highest point to the lowest point in 0.4 sec and the needle tip to travel a total distance in 0.9 sec.
Explanation:
Given that,
Frequency = 2.5 Hz
Amplitude = 1.27 cm
(a). We need to calculate the time
The frequency is the reciprocal of the time.
The time taken from highest point to lowest point
(b). Â We need to calculate the time
The time taken in one cycle = 0.4 sec
The distance covered  in one sec= 4 times x amplitude
We need to calculate the speed
Using formula of speed
We need to calculate the time
Hence, Â The tip of the needle to move from the highest point to the lowest point in 0.4 sec and the needle tip to travel a total distance in 0.9 sec.