Question

There are 2 toy cars facing each other at a distance of 500 cm from each other. each car moves forward by 100 cm at a speed of 50 cm/s and then moves backward by 50 cm at a speed of 25 cm/s. how long will it take for the cars to collide?

Answer 1

Answer:

14 seconds

Explanation:

distance between 2 cars =500 cm

first case,

distance = 100

speed =50 cm/s

t = d/s = 100 / 50 = 2 seconds

In first 2 seconds ,each car moves forward by 100 cm ,

total ,2 (car) × 100 (distance) = 200

500 -200 = 300 cm

second case,

distance =50 cm

speed = 25 cm/s

t =d/s = 50/25 = 2 seconds

in next 2 seconds ,each car moves backward by 50cm,

total ,2 (car) × 50 (distance) =100

300 + 100 =400 cm

thus for every 4 seconds the distance is reduced by 100cm.

500 to 400 = 4seconds

400 to 300= 4seconds

300 to 200 = 4 seconds

At the distance of 200,

process 1 : in 2 seconds ,when both cars moves forward by 100cm ,both cars get collide .

hence total

= 4 s + 4 s + 4 s + 2 s

=14 seconds

both cars get collide in 14 seconds.

Answer 2

${2}^{2} \gamma \beta \alpha \\ .23 = 4$

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