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Using second law of motion, derive the r...

Using second law of motion, derive the relation between force and acceleration. A bullet of `10g` strikes a sand-bag at a speed of `10^(3)ms^(-1)` and gets embedded after travelling `5cm`.Calculate
(i) the resistive force exerted by the sand on the bullet (ii) the time taken by the bullet to come to rest.

Text Solution

Verified by Experts

The required relation is `F=ma`
Mass of bullet, `m=10g=10^(-2)kg`
speed of bullet, `v=10^(3)ms^(-1)`
distance travelled, `s=5cm=5xx10^(-2)m`
As work done= `K.E` bullet
`:. Fxxs=1/2mv^(2)`
`F=(mv^(2))/(2s)=(10^(-2)(10^(3))^(2))/(2xx5xx10^(-2))=10^(5)N`
From `v=u+at`
`0=10^(3)+((-10^(5))/(10^(-2)))xxt, t=10^(3)/(10^(7))=10^(-4)s`
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