Which of the following describes an object in static equilibrium? a. a platypus lies motionless on the sand. b. a tuna speeds up from 2 m/s to 3 m/s c. a dolphin jumps out of the water d. a zebra shark swims at a constant speed of 8 m/s

Option A is the correct answer.

Explanation:

 Static equilibrium means an object object is at rest and is in a state of equilibrium.

If we examine options B, C and D we can see that, in each case object is in a state of motion.

B) Tuna is in a motion.

C) Dolphin is a motion.

D) Zebra is a motion

In option A platypus lies motionless on the sand, which is an example of static equilibrium.

so, option A is the correct answer.

a.   mass number from atomic number