question_answer 50)

  An object starting from rest travels 20 m in first 2 s and 160 m in next 4 s. What will be the velocity after 7s from the start?

Answer:

  Given, object starts from rest, u = 0, t = 2s and s = 20 m From second equation of motion,On putting u = 0 in above equation, Now, from first equation of motion, velocity after 7 s from the start v = u + at = 0 + 10 x 7 = 70 m/s