Question

a boy goes to market at an average speed of 29 km per hour. finding the market closes, he immediately returns back by the same path with an average speed of 40 km per hour. (a) average speed (b) average velocity for the complete journey.​​

Answer 1

Answer:

(a) average speed= 34.5km/hr

(b) average velocity for the complete journey=0km/hr

Explanation:

Given Information -

[assuming initial position as 'A' and market shop/final position as 'B']

• Speed from A to B = 29 km/hr
• Speed from B to A = 40 km

Given Questions on The basis of Understanding -

• (a) average speed.
• (b) average velocity for the complete journey.

Solution-

(a) average Speed -

Speed is obtained from the total distance travelled per time.

While average speed refers to the total distance per total time .

Average Speed-${\frac{total\:distance }{total\:time}}$

• $= \frac{29 + 40}{2}$

• $= \frac{69}{2}$

• $\bold\red{= 34.5km/hr}$

Average speed is 34.5km/hr.

____________________________

(b) average velocity for the complete journey-

Velocity is displacement per time, and if the intial and final positions are same, the velocity remains 0.

Average velocity in case of non-uniform motion is the sum of velocities upon time.

Average Velocity - ${\frac{total\:displacement}{total\:time}}$

• $= \frac{0}{2}$

• $\bold\red{= 0km/hr}$

Average velocity is 0km/hr.

Answer 2

Answer:

(a) average speed= 34.5km/hr

(b) average velocity for the complete journey=0km/hr

Explanation:

Given Information -

[assuming initial position as 'A' and market shop/final position as 'B']

Speed from A to B = 29 km/hr

Speed from B to A = 40 km

Given Questions on The basis of Understanding -

(a) average speed.

(b) average velocity for the complete journey.

Solution-

(a) average Speed -

Speed is obtained from the total distance travelled per time.

While average speed refers to the total distance per total time .

Average Speed-totaldistance

= \frac{29 + 40}{2} =

2

29+40

= \frac{69}{2} =

2

69

\bold\red{= 34.5km/hr}=34.5km/hr

Average speed is 34.5km/hr.

____________________________

(b) average velocity for the complete journey-

Velocity is displacement per time, and if the intial and final positions are same, the velocity remains 0.

Average velocity in case of non-uniform motion is the sum of velocities upon time.

Average Velocity - {\frac{total\:displacement}{total\:time}}

totaltime

totaldisplacement

= \frac{0}{2} =

2

0

\bold\red{= 0km/hr}=0km/hr

Average velocity is 0km/hr.