Estimate the acceleration that a cat undergoes as it jumps from the floor to a countertop.

Acceleration of the cat (after the initial moment of the jump) is -9.8 m/s^2

Explanation:

If we consider the motion of the cat just after the moment of the jump, and we neglect air resistance, we can notice that there is only one force acting on the cat: the force of gravity, which acts downward, and whose magnitude is equal to the weight of the cat:

(1)

where m is the cat's mass and g=-9.8 m/s^2 is the acceleration due to gravity.

Newton's second law states that the acceleration of the cat is given by

Re-arranging it,

And inserting eq.(1), we find

where the negative sign means the direction is downward.