Question

A particle travel half distance with uniform speed 40m/s and next half distance with uniform speed 80m/s calculate average speed.

Answer 1

Solution:-

Part I :-

• Speed ( s)= 40 m/s

Let the total distance traveled by the particle be d

• Distance(d') = d / 2

we know that ,

⟹ s = d' / t '

On rearranging ,

⟹ t ' = d ' / s

⟹ t ' = d / 2 x 40

⟹ t ' = d / 80

Part II :-

• Speed ( s")= 40 m/s

Let the total distance traveled by the particle be d

• Distance(d") = d / 2

we know that ,

⟹ s = d" / t "

On rearranging ,

⟹ t " = d " / s

⟹ t " = d / 2 x 80

⟹ t " = d / 160

Part III :-

⟹ Average speed = total distance / total time

⟹ Average speed = d / t' + t"

⟹ Average speed = d / d / 80 + d / 160

⟹ Average speed = d / 2d+d / 160

⟹ Average speed = d x160  / 3d

∴Average speed = 53.33 m /s