Question

A train accelerates from 10m/s to 20m/s in 20sec. Find the distance travelled by it.​

Answer 1

Answer:

300

Explanation:

V = u +at => a =20-10/20 => a = .5 m/sec2

v2-u2 = 2as => 400-100 = 2*.5*s => 300 = Distance traveled by train

Answer 2

Given:-

• Initial velocity (u) = 10 m/s
• Final velocity (v) = 20 m/s
• Time taken (t) = 20 seconds

To Find: Distance travelled at that period.

We know,

• 2as = v² - u²

and,

• a = (v - u)/t

where,

1. a = Acceleration,
2. s = Distance travelled,
3. v = Final velocity,
4. u = Initial velocity,
5. t = Time taken.

So, we can also write:-

2as = v² - u²

→ 2[(v - u)/t]s = v² - u²

→ 2[(20 m/s - 10 m/s)/20 s]s = (20 m/s)² - (10 m/s)²

→ 2(½ m/s²)s = (30 m/s)(10 m/s)

[∵ a² - b² = (a + b)(a - b)]

→ (1 m/s²)s = 300 m²/s²

→ s = (300 m²/s²)(s²/m)

→ s = 300 m

∴ So, it covered 300 m.