1. The water level at an ocean inlet has a depth, d, in metres, that varies with the time, t, in hours after midnight,
(-4)
12.4
+ 6. What is the water depth at 2:30 a.m., to the nearest hundredth
according to the equation d-5 sin 2x
of a metre?
2. When a pendulum 0.5 m long swings back and forth, its angular displacement from rest position, in radians, is
given by 0(t)=sin, where t is the time, in seconds. At what time(s) during the first 4 s is the pendulum
displaced 1 cm vertically above its rest position? (Assume the pendulum is at its rest position at t = 0.) ✓ ✓ ✓
Fig: 1