Why is it not a good idea to use a stopper when combining two unknown substances in   test?

Aroller coaster car is traveling down a track at 22 m/s. the car has a mass of 2000 kg. what is the kinetic energy of the car? a) 22,000 j b) 968,000 j c) 484,000 j d) 44,000 j

What is the molar mass of ca(cio4)2

Which three statements represent the benefits of performing experiments using computer simulations?