Question

Q. 1: The velocity of bullet is reduced from 200m/s to 100 m/s while traveling through a wooden block of
thickness 10 cm. The retardation, assuming it to be uniform will be:
A. 10 × 104 m/s2
B. 1.2 × 104 m/s2
C. 13.5 × 104 m/s2
D. 15 × 104 m/s2

Answer 1

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Q. 1: The velocity of bullet is reduced from 200m/s to 100 m/s while traveling through a wooden block of thickness 10 cm. The retardation, assuming it to be uniform will be:

A. 10 × 104 m/s2

B. 1.2 × 104 m/s2

C. 13.5 × 104 m/s2

D. 15 × 104 m/s2

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✳Option(D) 15× 10^4

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$\large{ \green{ \bold{ \star{given...}}}}$

✏Initial velocity = 200 m/s

✏Final Velocity = 100 m/s

✏Thickness of wooden board= 10 cm

$\large{ \green{ \bold{ \star{to \: find..}}}}$

✏Retardation of the body...?

$\large{ \sf{ \leadsto{ u \: must \: know....}}} \\ \\ \large{ \sf{ \red{2nd \: equation \: of \: motion...}}} \\ \huge{ \sf{ \boxed{ \purple{v {}^{2} - u {}^{2} = 2as}}}} \\ \\ \large{ \sf{v = final \: velocity}} \\ \\ \large{ \sf{u = initial \: velocity}} \\ \\ \large{ \sf{a = \: accleration }} \\ \\ \large{ \sf{s = distance \: or \: displacement}}$

$\large{ \sf{ \leadsto{using \: this \: formula...}}} \\ \\ \large{ \sf{ \implies{ {100}^{2} - {200}^{2} = 2 \times a \times \frac{10}{100} }}} \\ (\large{ \sf{ \red{1 \: cm = \frac{1}{100} m}}}) \\ \\ \large{ \sf{ \implies{a = \frac{10000 - 40000}{2 \times \frac{10}{100} } }}} \\ \\ \large{ \sf{ \implies{a = \frac{ - 30000 \times \cancel{100} \: 5}{ \cancel{20}} }}} \\ \\ \large{ \sf{ \implies{a = - 150000}}} \\ \\ \large{ \sf{ \red{ \implies{ \boxed{r = 15 \times 10 {}^{4} }}}}}$

$\large{ \sf{ \pink{retardation \: is \: negative \: accelertion}}}$

$\large{ \underline{ \orange{ \bold{ required \: answer \: is \: 15 \times 10 {}^{4} \: m \: s {}^{ - 2} }}}}$

$\large{\blue{\star{\bold{\underline{\underline{(additional\:information)}}}}}}$

3 equations of motion...

• v = u + at

• v² = u² + 2as

• s = ut + ½at²

Answer 2

Answer:

(d). 158*104m/s2

Explanation:

correct answer