Question

A ball of mass 250gm moving with a speed of 2m/s hits a ball normally .it rebounds with same speed if the two were in the contact for 10^-3 seconds.The average force exerted by the wall on the ball is?
PLEASE GIVE PROPER ANSWERS​​

Answer 1

GIVEN :-

• Mass = 250 g
• Speed = 2 m/s
• Time of contact = 10⁻³ sec
• The average force exerted by the wall on the ball = ?

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$\begin{gathered}:\implies \sf{ \Delta p = mv + mv}\\\\\end{gathered}$

$\begin{gathered}:\implies \sf{ \Delta p = 2(mv)}\\\\\end{gathered}$

Now we shall find the average force!!

$\begin{gathered}:\implies \sf{F = \dfrac{dp}{dt} }\\\\\end{gathered}$

$\begin{gathered}:\implies \sf{F = \dfrac{\Delta p}{\Delta t} }\\\\\end{gathered}$

$\begin{gathered}:\implies \sf{F = \dfrac{2mv}{\Delta t} }\\\\\end{gathered}$

$\begin{gathered}:\implies \sf{F = \dfrac{2 \times 0.25 \times 2}{ {10}^{ - 3}} }\\\\\end{gathered}$

$\begin{gathered}:\implies \sf F = \dfrac{2 \times 250 \times 10^{-3} \times 2}{ {10}^{ - 3}} \\\\\end{gathered}$

$\begin{gathered}:\implies \sf F = \dfrac{1000\times \cancel{10^{-3}}}{\cancel{{10}^{ - 3}}} \\\\\end{gathered}$

$:\implies \underline{\boxed{\mathfrak{\pink{ f = 1000 \: n}}}}$