SATHEE: Work Energy And Power Question 320

Work Energy And Power Question 320

Question: A ball of mass m hits a wall with a speed v making an angle $\frac{5 g}{14}$ with the normal. If the coefficient is e, the direction and magnitude of the velocity of ball after reflection from the wall will respectively be -

Options:

A) $\tan^{- 1} (\frac{\tan θ}{e}), v \sqrt{\sin^{2} θ + e^{2} \cos^{2} θ}$

B) $\tan^{- 1} (\frac{e}{\tan θ}), \frac{1}{v} \sqrt{e^{2} \sin^{2} θ + \cos^{2} θ}$

C) $\tan^{- 1} (e \tan θ), \frac{v}{e} \tan θ$

D) $\tan^{- 1} (e \tan α), v \sqrt{\sin^{2} θ + e^{2}}$

Show Answer

Answer:

Correct Answer: A

Solution:

[a] Let the angle of reflection be $θ$ ’ and the magnitude of velocity after collision be v’. As there is no force parallel to the wall, the component of velocity parallel to the surface remains unchanged.

Therefore, $v^{'} s i n θ^{'} = v sin θ \dots . (1)$

As the coefficient of restitution is e, for perpendicular component of velocity

Velocity of separation = e x velocity of approach

$- (v^{'} \cos θ^{'} - 0) = - e (v \cos θ - 0) \dots . (2)$

From (1) and (2)

$v^{'} = v \sqrt{\sin^{2} θ + e^{2} \cos^{2} θ}$

and $\tan θ^{'} = tan θ /e$

Work Energy And Power Question 320

Question: A ball of mass m hits a wall with a speed v making an angle $\frac{5 g}{14}$ with the normal. If the coefficient is e, the direction and magnitude of the velocity of ball after reflection from the wall will respectively be -

Options:

Answer:

Solution:

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Work Energy And Power Question 320

Question: A ball of mass m hits a wall with a speed v making an angle 5g14 with the normal. If the coefficient is e, the direction and magnitude of the velocity of ball after reflection from the wall will respectively be -

Options:

Answer:

Solution:

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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Question: A ball of mass m hits a wall with a speed v making an angle $\frac{5 g}{14}$ with the normal. If the coefficient is e, the direction and magnitude of the velocity of ball after reflection from the wall will respectively be -