Physics

Problem

A particle moves along a straight line, first covering a distance

d

in time

t_{1}

in one direction and then the same distance

d

back to the starting point in time

t_{2}

. a. (i) Show that the average speed for the complete trip is

\dfrac{2d}{t_{1}+t_{2}}

. b. (ii) Obtain an expression for the magnitude of the average velocity for the complete trip. c. (iii) Hence, state the condition on

t_{1}

and

t_{2}

under which the average speed equals the magnitude of the average velocity.