Question

A particles moving in a straight line covers half of the total distance with a speed of 3 m/s. The other half of the distance is covered in two equal time intervals with speeds of 4.5 m/s and 7.5 m/s. The average speed of the particle during this motion is (a) 4 m/s (b) 5 m/s (c) 5.5 m/s (d) 4.8 m/s

Answer 1

Answer: a)4m/s is the correct answer

Explanation:

Let the distance covered be 2d.

Time taken to cover d

(T) = d/3 ....(since, t=d/s)

Now other half is covered in equal intervals of time.. let them be t.

d = 4.5t+7.5t

d=12t

t=d/12

Average Speed = Total distance/Total time

= 2d/( d/3+d/12+d/12)

= 2d/3d/6

= 4m/s