Dana is on a train traveling at a speed of 20 km/h. Dana walks from the front of the train to the back of the train at a speed of 4 km/h. What is Dana's speed relative to the ground?

a.) 20 km/h

b.) 12 km/h

c.) 16 km/h

d.) 24 km/h

Option C

16 Km/h

Explanation:

Dana is moving in opposite direction compared to the train. If we denote w-velocity of train with respect to ground and u - velocity of passenger with respect to train and v-velocity of passenger we can using classical mechanics claim that v = w-u

v=20-4=16 km/h