If you throw a ball up with a velocity of 3 m/s, how long will it take for the ball to reach the top of its path? - 3.31 sec
- 2.31 sec
- 1.31 sec
- 0.31 sec

What is the relation between concentration of reactants and the rate of chemical reaction?

Long term exposure to waves can cause sunburns and skin cancer. a) visible b) infrared c) gamma rays d) ultraviole

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.