1.

A body is released from the top of the tower of height 100m . After 2 seconds it is stopped and then instantaneously released. what will be its height after next 3 seconds? [Take g=10m/s ^-2]1》40m2》35m3》45m4》30m​

Answer»

Given:

A BODY is released from the TOP of the tower of HEIGHT 100m . After 2 seconds it is stopped and then instantaneously released.

To find:

Height of body after next 3 seconds.

Calculation:

After 2 seconds , the height of the BALL above the earth will be:

\therefore \: h = 100 - y

=  >  \: h = 100 -  \bigg \{ut +  \dfrac{1}{2} g {t}^{2}  \bigg \}

=  >  \: h = 100 -  \bigg \{0 +  \dfrac{1}{2} g {t}^{2}  \bigg \}

=  >  \: h = 100 -  \bigg \{ \dfrac{1}{2} g {t}^{2}  \bigg \}

=  >  \: h = 100 -  \bigg \{ \dfrac{1}{2} g {(2)}^{2}  \bigg \}

=  > h = 100 - 20

=  > h = 80 \: m

Its stopped for an INSTANT and again released.

Let height after next 3 seconds be H.

\therefore \: H = 80 -( y2)

=  >  \: H = 80 - \bigg \{u(t2) +  \dfrac{1}{2} g {(t2)}^{2} \bigg \}

=  >  \: H = 80 - \bigg \{0 +  \dfrac{1}{2} g {(t2)}^{2} \bigg \}

=  >  \: H = 80 - \bigg \{ \dfrac{1}{2} g {(t2)}^{2} \bigg \}

=  >  \: H = 80 - \bigg \{ \dfrac{1}{2} g {(3)}^{2} \bigg \}

=  >  \: H = 80 - \bigg \{ 45\bigg \}

=  >  \: H = 35 \: m

So, final answer is :

\boxed{ \red{ \bold{ \large{ \: H = 35 \: m}}}}



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