Question

how much time willa oobject take to cover 7km with a acceleration of 10m/s^2 and initional velocity of 0 m/s

Answer 1

Answer:

11min 40 sec

Explanation:

s= 7km = 7000 m

a = 10 m/s^2

u = 0 m/s

By using s = u + at

t = (s-u)/a

= 7000/10

= 700 second

= 11 min 40 sec

Answer 2

S = 7 km = 7 × 10^3 m

u = 0 m/s

a = 10 m/s^2

We will use third equation of motion i.e

$s = ut + \frac{1}{2} a {t}^{2}$

That implies ->

$7000 = 0 \times t + \frac{1}{2} \times 10 \times {t}^{2} \\ \\ = > 7000 = 5 {t}^{2} \\ \\ = > {t}^{2} = 1400 \\ \\ = > t = + 10 \sqrt{10} \: \: and \: \: - 10 \sqrt{14} \\ \\since \: t \: cant \: be \: ( - )ve \: so \\ \\ = > t = 10 \sqrt{14}$

10√14 ≈ 37.4 seconds

Hope this helps !