Question

two cars A and B are approaching each other head on with speeds 20m/s and 10m/s respectively. when there separation is X and then A and B start braking at 4 m/s2 and 2 m/s2. minimum value of x to avoid collision is
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Answer 1

Dear Students,

● Answer -

(2) X = 75 m

◆ Explanation -

Let s1 & s2 be stopping distances for car A & car B respectively.

Applying Newton's 3rd law of kinematics to car A,

v1² = u1² + 2as

0 = 20² + 2×(-4) × s

s1 = 400 / 8

s1 = 50 m

Applying Newton's 3rd law of kinematics to car B,

v2² = u2² + 2as

0 = 10² + 2×(-2) × s

s2 = 100 / 4

s2 = 25 m

Therefore, minimum separation between cars at the time of breaking is -

X = s1 + s2

X = 50 + 25

X = 75 m

Hope I was useful.