Which one of the following statements is true concerning an object executing simple harmonic motion? (a) the object’s velocity is never zero. (b) the object’s acceleration is never zero. (c) the object’s velocity and acceleration are simultaneously zero. (d) the object’s velocity is zero when its acceleration is a maximum. (e) the object’s maximum acceleration is equal to its maximum velocity.

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.

If two parallel light rays hit a mirror, they will not be parallel to each other after they reflect.

The sound level near a noisy air conditioner is 70 db. if two such units operate side by side, the sound level near the, would bea. 70dbb. 73 dbc. 105 dbd 140 db