Question

A body with initial velocity 8 m/s moves along a straight line with constant acceleration and travels 640 m in 40 s. The average velocity during this interval is (A) 16 m/s (B) 4 m/s (C) 6 m/s (D) 0.2 m/s ​

Answer 1

(A) 16 m/s

Explanation:

Given :

displacement = 640 m

Initial velocity = 8 m/s

Time = 40 s.

=> Using = ut + 1/2 at²

=> 640 = 8 × 40 + 1/2 (a) ( 40 × 40 )

=> 640 = 320 + 1/2(a) (1600)

=> a = 640 - 320 / 800

=> a = 320/800

=> a = 0.40 m/s²

For average velocity:

=> (0.40) × (40)

=> 16 m/s