Time period is defined as the time required to complete one oscillation.
Frequency is defined as the number of oscillations per unit time.
Time = 4 sec.
Time Period = (Time taken) / (Number of Oscillations)
Time Period = (4/40) = 0.1 sec.
Frequency = (Number of Oscillations)/ (Time taken)Frequency = (40/4) =10Hz.
Therefore, time period is 0.1 sec and frequency is 10 Hz