In the diagram, the ship send sound(?) waves to the water, to determine if there is anything there. If there is something like a sunken ship shown in the diagram, the waves return in a shorter time hence you can understand if theres something or now. This is the principle of radars and sonars.
Answer:
There is no change, unless your mass is somehow at the quantum level, at which the concept of half-life breaks down.
Half life is a property of the specific radioactive isotope...NOT of the initial sample's mass.
Answer:
I think it's a true but I'm not the smartest
Answer:

Explanation:
The roller coaster begins with maximum kinetic energy and no gravitational potential energy. The gravitational potential energy reaches its maximum when roller coaster is upside down at the top of the circle. The physical model for the roller coaster is constructed by means of the Principle of Energy Conservation:

The minimum velocity is:

Let assume that radio of curvature is measured in meters. Hence:

