Laura takes her little brother for a walk in the park from the benches to the water fountain. Laura walks in a straight line while her brother runs in circles around her. They both take the same number of seconds to reach the water fountain. Which of these is true? [Hint: distance and speed are scalars, displacement and velocity are vectors] * 1 point Laura and her brother traveled the same distance. Laura’s brother had a greater displacement than Laura. Laura’s brother had a greater average velocity than Laura. Laura and her brother had the same average velocity.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

i'm pretty sure its b i might be wrong though!