Question

speed of a skier increases steadily from 8 m/s to 20 m/s in 60 Seconds calculate the average speed of the skier

Answer 1

GIVEN,

Initial speed of a skier = 8 m/s.

Final speed of a skier = 20 m/s.

Total time taken = 60 seconds.

TO FIND,

Average Speed of the skier = ??

SOLUTION,

Average speed = (Change in speed ) ÷ (Time taken)

= (20-8) ÷ 60

= 12÷60

=0.2

【::】 Average speed of the skier is 0.2 m/s.

Answer 2

Given : Initial speed of a skier , $\[{u_i}\]$ = 8 m/s.

Final speed of a skier, $\[{u_f}\]$= 20 m/s.

Total time taken = 60 seconds.

To Find :  Average speed of the skier.

Solution :

Initial speed of a skier , $\[{u_i}\]$ = 8 m/s.

Final speed of a skier, $\[{u_f}\]$= 20 m/s.

Total time taken = 60 seconds.

As speed of skier increases steadily,

Thus ,

Average speed = $\[\frac{{\left( {Initial{\text{ }}speed{\text{ }} + {\text{ }}final{\text{ }}speed} \right)}}{2}\]$

Average speed = $\[\frac{{{u_i} + {u_f}}}{2}\]$ = $\[\frac{{8 + 20}}{2}\]$ = 14m/s  

 

Hence average speed of skier is 14m/s