Depends in a launage or just in general the little hand is the mins and the big hand is the big numbers whole numbers time
low speed means non relativistic.
the velocities relative to an observer outside the train are added.
51 m/s.
Were ita light wave, rather than Emma, the speed wold not depend on the speed of the train. Though that may sound surprising, I think it's true. Special relativity says more about this.
Special relativity "shows up" when the speeds get very high indeed.
Answer: B, Ice has a lower density than liquid water.