Question 147: Motion in 1D

Question

A particle covers half of its total distance with speed v
1
and the rest half distance with speed v
2
. Its average speed during the complete journey is

Accepted Answer

Let total distance = 2S
Let particle take t
1
time to cover first S distance,
$$ 	herefore $$ t
1
= $${S \over {{v_1}}}$$
Let particle take t
2
time to cover last S distance,
$$ 	herefore $$ t
2
= $${S \over {{v_2}}}$$
$$ 	herefore $$ Average speed = $${{2S} \over {{S \over {{v_1}}} + {S \over {{v_2}}}}}$$ = $${{2{v_1}{v_2}} \over {{v_1} + {v_2}}}$$

Answer

$${{{v_1} + {v_2}} \over 2}$$

Answer

$${{{v_1}{v_2}} \over {{v_1} + {v_2}}}$$

Answer

$${{2{v_1}{v_2}} \over {{v_1} + {v_2}}}$$

Answer

$${{v_1^2v_2^2} \over {v_1^2 + v_2^2}}$$

Motion in 1D

A particle covers half of its total distance with speed v 1 and the rest half distance with speed v 2 . Its average speed during the complete journey is

Choose the correct answer: