A football player runs 80 yards for a touchdown! It takes him 20 seconds. What is his speed?

What are the charges of the subatomic particles by choosing the answer from the drop down menu. protons have a (+1,0,or-1). (protons,neutrons,electrons) have a 0 charge. 3.) electrons have a (+1,0,-1)

Can someone me with questions 15 to 17 plz.

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.