Answer:
a) t = 1.75 s
b) x = 31.5 m
Step-by-step explanation:
a) The time at which Tom should drop the net can be found using the following equation:

Where:
: is the final height = 0
y₀: is the initial height = 15 m
g: is the gravity = 9.81 m/s²
: is the initial vertical velocity of the net = 0 (it is dropped from rest)


Hence, Tom should drop the net at 1.75 s before Jerry is under the bridge.
b) We can find the distance at which is Jerry when Tom drops the net as follows:


Then, Jerry is at 31.5 meters from the bridge when Jerry drops the net.
I hope it helps you!