How much kinetic energy does a 7.2-kg dog need to make a vertical jump of 1.2 m the acceleration due to gravity is 9.8 ms2?

The kinetic energy with which he leaves the ground must be at least equal to

the potential energy he will have when he reaches 1.2 meters above it.

Potential energy = (mass) x (gravity) x (height) = (7.2) x (9.8) x (1.2) = 84.672 Joules.

If the dog has that much KE AND his speed off the ground is entirely vertical,

then he'll just reach 1.2 meters.

(The same argument applies if the dog is a female. I just naturally wrote a male

dog into the solution because both of my dogs are boys.)