Question

5.
When we start typing in a word processor text appears at the position where the
is placed.​

Answer 1

Explanation:

GIVEN :-

Mass of ball ( m ) = 1 kg.

Final velocity ( v ) = - 8 m/s [ Rebounds after striking the wall ]

Initial velocity ( u ) = 8 m/s.

Time ( T ) = 0.1 sec.

TO FIND :-

The change in momentum.

The Force applied by the wall.

SOLUTION :-

As we know that change in momentum is given by,

\begin{gathered} \implies \displaystyle \sf \: \Delta p = mv - mu \\ \end{gathered}

⟹Δp=mv−mu

\begin{gathered} \implies \displaystyle \sf \: \Delta p =m(v - u) \\ \end{gathered}

⟹Δp=m(v−u)

\begin{gathered} \implies \displaystyle \sf \: \Delta p =1( - 8- 8) \\ \end{gathered}

⟹Δp=1(−8−8)

\begin{gathered} \implies \displaystyle \sf \: \Delta p =1( - 16) \\ \end{gathered}

⟹Δp=1(−16)

\begin{gathered} \implies \underline{ \boxed{ \displaystyle \sf \: \Delta p = - 16 \: kg.ms ^{ - 1} }} \\ \end{gathered}

⟹

Δp=−16kg.ms

−1

Hence the change in momentum if the ball rebounds with the same speed is -10 kg.m/s.

Now as we know that Force is given by,

\begin{gathered}\implies \displaystyle \sf \: F = mass \times Acceleration \\ \end{gathered}

⟹F=mass×Acceleration

Now as we know that , Acceleration = ( v - u )/t,

\begin{gathered}\implies \displaystyle \sf \: F = 1\times \frac{v - u}{t} \\ \end{gathered}

⟹F=1×

t

v−u

\begin{gathered}\implies \displaystyle \sf \: F = \frac{ - 8 - 8}{0.1} \\ \end{gathered}

⟹F=

0.1

−8−8

\begin{gathered}\implies \displaystyle \sf \: F = \frac{ - 16}{0.1} \\ \end{gathered}

⟹F=

0.1

−16

\begin{gathered}\implies \underline{ \boxed{\displaystyle \sf \: F = - 160\: N}} \\ \end{gathered}

⟹

F=−160N

Hence The Force applied by the wall is -160 N which means that Force is applied on apposite direction.