Question

A student rides on a train traveling at Vt = 36ikm/hr (with the respect to the ground). What are the speed and the velocity of the student with respect to the ground if he runs at 5.0im/s? -5.0 m/s? 5.0j m/s perpendicular to the direction of motion of the train?

Answer 1

Let's convert km/hr to m/s

36km/hr * 1000m/km * hr/3600s = 10m/s
how convenient.

at 5.0i the velocities just add: 10i + 5i = 15im/s

same for -5i: 10i-5i=5im/s

when running at 5.0j, we have 10i+5j, so the speed is sqrt(100+25) = 11.2m/s

direction θ has tanθ = 5/10, so θ=26.6°

36km/hr? what is this, a freight train?

Answer 2

Thank you very much! I appreciate your help! :)