# physics

posted by on .

a train moving at constant velocity of 54 k mph moves east wards for 30 min, then due to north with the same speed for 40 min. What is the average velocity of the train during the run?(in k mph)

• physics - ,

I assume that your "k mph" is really kilometers per hour (km/h)

In 70 minutes, the train goes (1/2)*54 = 27 km east and (2/3)*54 = 36 km north.

It ends up sqrt[(27)^2 + (36)^2]= 45 km from where it started.

The magnitude of the average velocity
is 45 km/(7/6 h) = 38.57 km/h
(70 minutes = 7/6 hour)

The direction of the avg velocity is
arctan 36/27 = 53.13 degrees north of east.

• physics - ,

Kmph
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0}