Question

class 9 chapter 8 motion​

Answer 1

Explanation:

(i) Acceleration :

v = u + at

⇒ 20 = 0 + a * 120{∵2 minutes = 120 seconds}

⇒ 20 = 120a

⇒ a = (1/6) m/s²

(ii) Distance travelled :

v² = u² + 2as

⇒ 20² = 0² + 2 * (1/6) * s

⇒ 400 = 0 + (1/3) * s

⇒ s = 1200 m

Hope it helps!

Answer 2

Given :

• Initial Velocity (u) = 0 m/s

• Final Velocity (v) = 20 m/s

• Time (t) = 2 minutes = 120 seconds

To Find :

• Acceleration (a)

• Distance Travelled (s)

Solution :

Let's find the acceleration first :

We know that,

★ Acceleration = Final Velocity - Initial Velocity/Time taken

→ a = v - u/t

→ a = 20 - 0/120

→ a = 20/120

→ a = 0.167 m/s² (Approx)

$\therefore$ Acceleration produced by the train is 0.167m/s²

___________________

Let's find the Distance covered now :

From,2nd equation of motion :

★ s = ut + ½ at²

→ s = (0)(120) + ½ (0.167) (120)²

→ s = 0 + ½ × 0.167 × 120 × 120

→ s = 2404.8/2

→ s = 1202.4 m (Approx)

$\therefore$ Total Distance Covered is 1202.4 m.