Question

plz help................ ​

Answer 1

$\blue{\bold{\underline{\underline{Answer:}}}}$

$\green{\tt{\therefore{T_{1}:T_{2}=1:4}}}$

$\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

$\green{\underline \bold{Given :}} \\ \tt:\implies Length( l_{1}) = 1 \: m \\ \\ \tt:\implies Length( l_{2}) = 16\: m \\ \\ \red{\underline \bold{To \: Find :}} \\ \tt: \implies Comparison \:of \: time \: period =?$

• According to given question :

$\bold{As \: we \: know \: that} \\ \tt: \implies T_{1} = 2\pi \sqrt{ \frac{ l_{1} }{g} } \\ \\ \tt: \implies T_{1} =2\pi \sqrt{ \frac{1}{g} } - - - - - (1) \\ \\ \bold{Similarly : } \\ \tt: \implies T_{2} = 2\pi \sqrt{ \frac{ l_{2}}{g} } \\ \\ \tt: \implies T_{2} = 2\pi \sqrt{ \frac{16}{g} } - - - - - (2) \\ \\ \text{Taking \: ratio \: of \: (1) \: and \: (2)} \\ \\ \tt: \implies \frac{ T_{1} }{ T_{2} } = \frac{ 2\pi\sqrt{ \frac{1}{g} } }{ 2\pi \sqrt{ \frac{16}{g} } } \\ \\ \tt: \implies \frac{ T_{1} }{ T_{2} } = \sqrt{ \frac{1}{g} } \times \sqrt{ \frac{g}{16} } \\ \\ \tt: \implies \frac{ T_{1} }{ T_{2} } = \sqrt{ \frac{1}{16} } \\ \\ \tt: \implies \frac{ T_{1} }{ T_{2} } = \frac{1}{4} \\ \\ \green{\tt: \implies { T_{1} } : { T_{2} } =1 : 4} \\ \\ \green{\tt \therefore Time \: period \: of \: l_{2} \: is \:4 \: times \: of \: time \: period \: of \: l_{1}}$

Answer 2

Answer:

mass of bullet should be =10gm=0.01kg

initial velocity (U)of bullet=1000m/s

final velocity (V)=0m/s(because it has stopped after striking sand)

displacement of bullet=5cm=0.05m

a) using 2as=V ²-U²

2(a)(0.05)=0²-1000²

2a(5/100)=-1000000

2a(1/20)=-1000000

a(1/10)=-1000000

a=-10000000=-10power7

acceleration of bullet is -10power7or -10000000

by using F=ma

F=0.01(10000000)

F=1/100(10000000)

F=-100000N

there fore resistive force of bullet =-100000N

b) by using a=v-u/t

-10000000=0-1000/t

-10000000=-1000/t

-10000=t

or

t=-10⁴seconds

hope this helps you