An object of m, kg with speed of v, m/s strikes a wall at an angle θ and rebounds at same speed and

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4-1.Newton's Laws of Motion

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An object of $m\, kg$ with speed of $v\, m/s$ strikes a wall at an angle $\theta$ and rebounds at the same speed and same angle. The magnitude of the change in momentum of the object will be

A$2m\,v\,\cos \theta $

B$2\,m\,v\,\sin \theta $

C$0$

D$2\,m\,v$

Solution

(a) ${\overrightarrow P _1} = m\,v\,\sin \theta \,\hat i – m\,v\,\cos \theta \,\hat j$
and ${\overrightarrow P _2} = m\,v\,\sin \theta \,\hat i + \,m\,v\,\cos \theta \,\hat j$
So change in momentum
$\overrightarrow {\Delta P} = {\overrightarrow P _2} – {\overrightarrow P _1} = 2\,m\,v\,\cos \theta \,\hat j,$$|\Delta \overrightarrow P |\, = 2\,m\,v\,\cos \theta $

Standard 11

Physics

Two billiard balls of equal mass $30 \,{g}$ strike a rigid wall with same speed of $108\, {kmph}$ (as shown) but at different angles. If the balls get reflected with the same speed then the ratio of the magnitude of impulses imparted to ball $'a'$ and ball $'b'$ by the wall along $'X'$ direction is :

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(JEE MAIN-2021)

Below figure shows the position-time graph of a body of mass $0.04\; kg$. Suggest a suitable physical context for this motion. What is the time between two consecutive impulses received by the body ? What is the magnitude of each impulse ?

easy

A body of mass $3\,kg$ is acted on by a force which varies as shown in the graph below. The momentum acquired is given by ……….. $N-s$

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Resultant of action and reaction is zero. (True or False)

easy

Figure shows the position-time graph of a particle of mass $4 \,kg$. What is the

$(a)$ force on the particle for $t\, <\, 0, t \,> \,4\; s, 0 \,<\, t \,< \,4\; s$?

$(b)$ impulse at $t=0$ and $t=4 \;s ?$ (Consider one-dimensional motion only).

medium

An object of $m\, kg$ with speed of $v\, m/s$ strikes a wall at an angle $\theta$ and rebounds at the same speed and same angle. The magnitude of the change in momentum of the object will be

Solution

Similar Questions

Below figure shows the position-time graph of a body of mass $0.04\; kg$. Suggest a suitable physical context for this motion. What is the time between two consecutive impulses received by the body ? What is the magnitude of each impulse ?

A body of mass $3\,kg$ is acted on by a force which varies as shown in the graph below. The momentum acquired is given by ……….. $N-s$

Resultant of action and reaction is zero. (True or False)

Figure shows the position-time graph of a particle of mass $4 \,kg$. What is the $(a)$ force on the particle for $t\, <\, 0, t \,> \,4\; s, 0 \,<\, t \,< \,4\; s$? $(b)$ impulse at $t=0$ and $t=4 \;s ?$ (Consider one-dimensional motion only).

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Figure shows the position-time graph of a particle of mass $4 \,kg$. What is the

$(a)$ force on the particle for $t\, <\, 0, t \,> \,4\; s, 0 \,<\, t \,< \,4\; s$?

$(b)$ impulse at $t=0$ and $t=4 \;s ?$ (Consider one-dimensional motion only).