A massless length of twine can withstand a maximum tension of 490 N. The twine is used to spin a 28-kg ball in horizontal circular motion of radius 1.8 m. The ball is spun faster and faster until the twine breaks. What was the maximum speed of the ball? 7.2 m/s
3.2 m/s
5.6 m/s
11 m/s

What energy is it when you flip on a switch on a lamp

Inside a flashbulb, oxygen surrounds a thin coil of magnesium. when the flashbulb is set off, a chemical reaction takes place in which magnesium combines with oxygen to form magnesium oxide. which of the chemical equations matches the reaction above? a. mg + o2 mgo2 + energy b. 2mg + o mg2o + energy c. 2mg + o2 2mgo + energy d. mg + o mgo + energy

Who determined the nature of chemical bonds?