The answer is b. because they move freely
The energy of the baby is gravitational potential energy, and it is equal to the weight of the baby times its height from the ground:

where
mg=20 N is the weight (the mass times the gravitational acceleration)
h=1.5 m is the height from the ground
If we plug the numbers into the equation, we find
Answer:
the questions they could ask would be:
how much will the temperature change?
how much pressure will there be?
how durable does the equipment need to be?
how do we know if we will run into a water pocket or a magma pocket?
Explanation:
Answer:
We can't actually see the force of gravity BUT we can see its effect.