Adults typically make a bigger splash when they jump into a swimming pool because they have more mass than children. The size of the splash that is produced when an object enters the water is determined by the amount of kinetic energy that the object has. This, in turn, is determined by the object's mass and velocity.
Since adults have more mass than children, they have more kinetic energy when they jump into the pool. This means that when they enter the water, they transfer more kinetic energy to the water, resulting in a larger splash.
In addition to having more mass, adults also typically have a higher velocity when they jump into the pool. This is because they are generally taller and can generate more force when they jump. As a result, they enter the water with more kinetic energy, which leads to a larger splash.
Overall, the reason that adults make a bigger splash when they jump into the pool is that they have more mass and a higher velocity, which results in more kinetic energy being transferred to the water. This causes a larger splash to be produced.