A train left the station at 9:00am. The next stop was 629 km south. It arrived at 2:00pm the same day. What was its speed?

Taylor's experiment: 1. accurately measured the speed of light 2. locked together the phases of two light sources so that the interference pattern would not shift 3. showed that man's reaction time was much slower than the speed of light 4. showed that individual photons have wave characteristics

In a given chemical reaction, the energy of the products is greater than the energy of the reactants. which statement is true for this reaction?

Describe uniform velocity and variable velocity in short