Physics, asked by Atαrαh, 9 months ago

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Answers

Answered by JunoirJumper
31

In the first case, (when going upward)

• Initial speed = \sf{v_o}

• Acceleration while ball is moving upward :-

\sf{\dfrac{w+f}{m}}

We know,

\sf{v_f^2=v_i^2 +2\overrightarrow{a}.\overrightarrow{s}}

\sf{\implies 0=v_o^2-2s\bigg(\dfrac{w+f}{m} \bigg)}\\\\\sf{\implies -v_o^2=-2s\bigg(\dfrac{w+f}{m} \bigg)}\\\\\sf{\implies v_o^2=2s\bigg(\dfrac{w+f}{m} \bigg)}\\\\\sf{\implies 2s=\dfrac{v_o^2}{\bigg(\dfrac{w+f}{m}  \bigg)} }\\\\\sf{\implies s=\dfrac{v_o^2}{2\bigg(\dfrac{w+f}{m}  \bigg)} }

◘ In the second case, (when coming down)

\sf{v_i=0}

\sf{a=w+f}

Now,

\sf{v_f^2=v_i^2+2 \overrightarrow{a}.\overrightarrow{s}}

Putting the values of a and s :-

\sf{v_f^2=\dfrac{2\times (w-f)v_o^2}{2(w+f)} }\\\\\sf{\hookrightarrow v_f^2=\dfrac{ (w-f)v_o^2}{(w+f)} }\\\\\sf{\hookrightarrow v_f= \sqrt{\dfrac{(w-f)v_o^2}{(w+f)}  }}\\\\\sf{\hookrightarrow v_f= v_o\sqrt{\dfrac{(w-f)}{(w+f)} } }\\\\\boxed{\boxed{\sf{\color{magenta}{\hookrightarrow v_f= v_o\bigg(\dfrac{w-f}{w+f} \bigg)^\frac{1}{2}}}}}

Hence, the answer is option (a).

Answered by Anonymous
1

Answer:

◘ In the first case, (when going upward)

• Initial speed = \sf{v_o}v

o

• Acceleration while ball is moving upward :-

\sf{\dfrac{w+f}{m}}

m

w+f

We know,

\sf{v_f^2=v_i^2 +2\overrightarrow{a}.\overrightarrow{s}}v

f

2

=v

i

2

+2

a

.

s

\begin{gathered}\sf{\implies 0=v_o^2-2s\bigg(\dfrac{w+f}{m} \bigg)}\\\\\sf{\implies -v_o^2=-2s\bigg(\dfrac{w+f}{m} \bigg)}\\\\\sf{\implies v_o^2=2s\bigg(\dfrac{w+f}{m} \bigg)}\\\\\sf{\implies 2s=\dfrac{v_o^2}{\bigg(\dfrac{w+f}{m} \bigg)} }\\\\\sf{\implies s=\dfrac{v_o^2}{2\bigg(\dfrac{w+f}{m} \bigg)} }\end{gathered}

⟹0=v

o

2

−2s(

m

w+f

)

⟹−v

o

2

=−2s(

m

w+f

)

⟹v

o

2

=2s(

m

w+f

)

⟹2s=

(

m

w+f

)

v

o

2

⟹s=

2(

m

w+f

)

v

o

2

◘ In the second case, (when coming down)

• \sf{v_i=0}v

i

=0

• \sf{a=w+f}a=w+f

Now,

\sf{v_f^2=v_i^2+2 \overrightarrow{a}.\overrightarrow{s}}v

f

2

=v

i

2

+2

a

.

s

Putting the values of a and s :-

\begin{gathered}\sf{v_f^2=\dfrac{2\times (w-f)v_o^2}{2(w+f)} }\\\\\sf{\hookrightarrow v_f^2=\dfrac{ (w-f)v_o^2}{(w+f)} }\\\\\sf{\hookrightarrow v_f= \sqrt{\dfrac{(w-f)v_o^2}{(w+f)} }}\\\\\sf{\hookrightarrow v_f= v_o\sqrt{\dfrac{(w-f)}{(w+f)} } }\\\\\boxed{\boxed{\sf{\color{magenta}{\hookrightarrow v_f= v_o\bigg(\dfrac{w-f}{w+f} \bigg)^\frac{1}{2}}}}}\end{gathered}

v

f

2

=

2(w+f)

2×(w−f)v

o

2

↪v

f

2

=

(w+f)

(w−f)v

o

2

↪v

f

=

(w+f)

(w−f)v

o

2

↪v

f

=v

o

(w+f)

(w−f)

↪v

f

=v

o

(

w+f

w−f

)

2

1

Hence, the answer is option (a).

Please brainlest me the answer

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