A ball is rolling down a hill at + 1.0 m/s, The ball is uniformly accelerating at

+4.9 m/s?, What will the ball's velocity be 4.0 s later?

+8.9 x 100° m/s

+2.0 x 10^1 m/s

+2.1 x 10^1 m/s

-1.9 x 10^1 m/s

2.1*10¹ m/s

Explanation:

Given:

v₀ = 1.0 m/s

a = 4.9 m/s²

t = 4.0 s

Find: v

v = at + v₀

v = (4.9 m/s²) (4.0 s) + (1.0 m/s)

v = 20.6 m/s

Rounded to two significant figures, the velocity is 21 m/s.

In scientific notation, the velocity is 2.1*10¹ m/s.