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Two cars approach each other from the opposite direction wit...
Physics
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Two cars approach each other from the opposite direction with the velocity 20m/s and 40m/s if they are 400m apart. Calculate

I)the time the two cars passes each other.

Ii)the distance between them after 15s

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Ghana
04 October 2020

School not set Nigeria
05 October 2020
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I) Since the two cars are moving towards each other, they will pass each other when they cover the distance between them (400m)

Let s1 and s2 be the distance covered by both cars.

s1 + s2 = 400 ---------- eqn(1)

v1 = s1 / t1

s1 = v1t1

S2 = v2t2

v1t1 + v2t2 = 400

Assuming both cars are moving at the same time,

t1 = t2 = t

v1t + v2t = 400

(V1 + v2)t = 400

(20 + 40)t = 400

60t = 400

t = 400/60

t = 6.67 seconds

Ii) distance between them after 15 seconds = 400 + (20 + 40)(15)

= 1300m

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Ana,
Please what formula did you use for the ii)
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s + s1 + s2 = s + v1t + v2t = s + (v1 + v2)t
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Ana,
But why isn't it s=(v1+v2) rather
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