SATHEE: Centre of Mass 3 Question 21

Centre of Mass 3 Question 21

24. The speed of the block at point $B$ immediately after it strikes the second incline is

(a) $\sqrt{60} m / s$

(b) $\sqrt{45} m / s$

(d) $\sqrt{15} m / s$

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Answer:

Correct Answer: 24. (b)

Solution:

Between $A$ and $B$ , height fallen by block

$h_{1} = \sqrt{3} \tan 60^{\circ} = 3 m$

$∴$ Speed of block just before striking the second incline,

$v_{1} = \sqrt{2 g h_{1}} = \sqrt{2 \times 10 \times 3} = \sqrt{60} m s^{- 1}$

In perfectly inelastic collision, component of $v_{1}$ perpendicular to $B C$ will become zero, while component of $v_{1}$ parallel to $B C$ will remain unchanged.

$∴$ Speed of block $B$ immediately after it strikes the second incline is,

$v_{2} =$ component of $v_{1}$ along $B C$

$\begin{aligned} = v_{1} \cos 30^{\circ} = (\sqrt{60}) \frac{\sqrt{3}}{2} \\ = \sqrt{45} m s^{- 1} \end{aligned}$

Centre of Mass 3 Question 21

24. The speed of the block at point $B$ immediately after it strikes the second incline is

Answer:

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Centre of Mass 3 Question 21

24. The speed of the block at point B immediately after it strikes the second incline is

Answer:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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24. The speed of the block at point $B$ immediately after it strikes the second incline is