I really need help John's mass is 55kg when he is standing on the edge of a diving
board 24m high. a. Find his mechanical energy.

What is it?

E = 12.9 kJ

Explanation:

Given that,

Mass of John, m = 55 kg

It is standing on the edge of a diving board which is at a height of 24 m.

We need to find his mechanical energy. The mechanical energy of John is equal to its potential energy such that,

E = mgh

E = 55  kg × 9.8 m/s² × 24

E = 12936  J

or

E = 12.9 kJ

So, his mechanical energy is equal to 12.9 kJ.

the small 0.38-kg slider is known to move from position a to position b along the vertical-plane slot. determine (a) the work done on the body by its weight and (b) the work done on the body by the spring. the distance r = 0.70 m, the spring modulus k = 154 n/m, and the unstretched length of the spring is 0.53 m

explanation:

-reverse card

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.