Question

the velocity of a bullet is reduced from 200m per sec to 100m per second while travelling through a wooden block of thickness 10 cm. the retardation assuming it to be uniform will be?

Answer 1

Retardation = (u² - v²) / (2S)
= [(200 m/s)² - (100 m/s)²] / (2 × 0.1 m)
= 1.5 × 10⁵ m/s²

Retardation of bullet in the block is 1.5 × 10⁵ m/s²

Answer 2

Answer:

Explanation:

Solution,

Here, we have

Initial velocity, u = 200 m/s

Final velocity, v = 100 m/s

Distance covered, s = 10 cm = 0.10 m.

(Converted cm to m)

To Find,

Acceleration, a = ?

According to the 2nd equation of motion,

We know that,

v² - u² = 2as

So, putting all the values, we get

v² - u² = 2as

⇒ (100)² - (200)² = 2 × a × 0.10

⇒ 10000 - 40000 = 0.2a

⇒ - 30000 = 0.2a

⇒ - 30000/0.2 = a

⇒ a = - 150000 m/s²

⇒ a = - 15 × 10⁴ m/s²

Hence, the retardation will be - 15 × 10⁴ m/s².