Multiple choice

A particle moving along a straight line travels half of the distance with uniform speed $\displaystyle 30\ m/s$ and remaining half of the distance with speed $60$ $\displaystyle m/s$. The average speed of the particle is

  1. $\displaystyle 45\ m/s$
  2. $\displaystyle 42\ m/s$
  3. $\displaystyle 40\ m/s$
  4. $\displaystyle 50\ m/s$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The average speed for equal distances is given by the harmonic mean formula: 2*v1*v2 / (v1 + v2). Substituting 30 and 60 gives 2*30*60 / (30 + 60) = 3600 / 90 = 40 m/s.

AI explanation

When equal distances are traveled at two different speeds, apply the average speed formula 2xy / (x + y). Substituting the given speeds gives (2 * 30 * 60) / (30 + 60), which simplifies to 3600 / 90. The average speed of the particle is 40 m/s.

Keep practicing — related questions