Which of the following statements is accurate?

a. if an object's velocity is changing, it's either experiencing acceleration or deceleration.
b. if an object's velocity decreases, then the object is accelerating.
c. if an object is said to be decelerating, its velocity must be increasing.
d. if an object's velocity remains constant, its acceleration must be increasing.

A6,600 kg train car moving at +2.0 m/s bumps into and locks together with one of mass 5,400kg moving at -3.0m/s. what is their final velocity? +0.50 m/s -1.0 m/s +2.5 m/s -0.25 m/s

Write a question about how changing temperature affects the gas inside the sports ball

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.