Can anyone help me how to solve it??

Question

A car is moving with uniform velocity of 61 km/h along a straight road for 10 mins. The driver then rapidly speeds up and then drives 39 km in 20 minutes. What is the average velocity in km/hr during the entire trip?

Answer 1

The definition of average velocity is total displacement / total time interval. In terms of the 1st and 2nd legs of the trip (ignoring the time and displacement of the acceleration phase), the equation is

v_avg = (v₁t₁ + v₂t₂)/(t₂ + t₁) which is just the weighted average of velocity with time.

I'll leave the plugging in to you. It's better form to use hours for time, but it is unnecessary here because the time units cancel.

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