A particle accelerates uniformly from a speed of 30 cm/s to 40 cm/s in 5 s and thereafter moves at a constant speed of 40 cm/s for an additional 3 s.The average speed over this total time interval is
A)35 cm/s
B)27 cm/s
C)0.45 cm/s
D)37 cm/s
E)73 cm/s

Question

Quizplus · Accepted Answer

Average speed = Total distance travelled / Total time takenTotal distance travelled = (30 + 40) / 2 * 5 + 40 * 3 = 350 cmTotal time taken = 5 + 3 = 8 sAverage speed = 350 / 8 = 43.75 cm/s

A Particle Accelerates Uniformly from a Speed of 30 Cm/s