Which of the following is an example of a contact force?

a. a magnet moving a metal object
b. gravity causing a rock to move
c. a person pushing a box across the floor
d. a person falling out of the sky

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)

When would a bouncy ball have the most potential energy

Mike and mitchell decide to have a foot race. they mark off a stretch of 100 yards, and recruit cindy to work the stopwatch. after running the race and looking at the results, cindy declared that mitchell was the fastest. so how did the boys times compare?