Question

A runner run 100 m.in 10s ,then turns around and jogs 50m back towards the starting point in 30s.find his (1) average speed (2) average Velocity.

Answer 1

Given:

A runner run 100 m.in 10s ,then turns around and jogs 50m back towards the starting point in 30s.

To find:

• Average speed

• Average Velocity

Calculation:

Average speed is defined as the total distance divided by the total time taken to cover that distance.

$\rm{avg. \: speed = \dfrac{total \: distance}{total \: speed} }$

$= > \rm{avg. \: speed = \dfrac{d1 + d2}{t1 + t2} }$

$= > \rm{avg. \: speed = \dfrac{100 + 50}{10 + 30} }$

$= > \rm{avg. \: speed = \dfrac{150}{40} }$

$\boxed{ = > \rm{avg. \: speed = 3.75 \: m {s}^{ - 1} }}$

Average Velocity is defined as the total displacement divided by the total time taken to cover that displacement.

$\rm{avg. \: velocity = \dfrac{total \: displacement}{total \: speed} }$

$= > \rm{avg. \: velocity = \dfrac{100 - 50}{10 + 30} }$

$= > \rm{avg. \: velocity = \dfrac{50}{40} }$

$= > \rm{avg. \: velocity = \dfrac{5}{4} }$

$\boxed{ = > \rm{avg. \: velocity = 1.25 \: m {s}^{ - 1} }}$

Hope It Helps.

Answer 2

Answer:

1.25m/s

Explanation:

average Velocity-> total displacement

                              --------------------------------

                                       total time

=>       (100-50)m  

         ----------------    =  1.25 m/s

             (10+30)