What does it mean to say that the speed of a vehicle is 40 mi/h?

Which statement best describes who the period and frequency of electromagnetic was change between gamma rays and microwaves? a) the period and frequency stay the same. b) the period increases and the frequency decreases. c) the period decreases and the frequency increases. d) the period increases and the frequency increases.

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Will mark as brainliest how does a catapult increase the trajectory of an object? ps. answer as if u were a 5th grader