First slide

The 3 equation for uniform acc

Question

A bullet emerges from a barrel of length 1.2 m with a speed of $640 {ms}^{- 1}$ . Assuming constant acceleration, the approximate time that it spends in the barrel after the gun is fired, is

Moderate

A

4 ms
B

40 ms
C

$400 μs$
D

1 s

Solution

Given, s = 1.2 m, v = $640 {ms}^{- 1}$
$a = ?; u = 0; t = ?$
$2 a s = v^{2} - u^{2}$
$\Rightarrow$ 2a x 1. 2 = 640 x 640
$\Rightarrow$ $a = \frac{8 x 64 x 1000}{3} m / s$
v = u + at
$\Rightarrow$ $t = \frac{v}{a} = \frac{640 \times 3}{8 \times 64 \times 100} s = 3.75 \times 10^{- 3} s \approx 4 ms$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App