Question

Analyse the following table showing variation of image distance (v) with object distance (u) in case of a convex lens and answer the questions that follow (Question 4 & 5)



4. Write the serial number of the observation which is not correct. *

1 point

1

3

4

5​

Answer 1

$\huge{\underline{\mathtt{\red{A}\pink{n}\green{s}\blue{w}\purple{e}\orange{r}\red{♡}\pink{~}}}}$

Total height =100m=S1+S2

Using equation of motion,

For first ball

S1=ut+21gt2

where,

S= Distance

u= Initial velocity

g= acceleration due to gravity

t= time

S1=0−21gt2

For second ball

S2=40t+21gt2

S2=40t−S1________(i)

Putting the value of S1 in equation (i)

S2+S1=40t

100=40t

t=2.5sec

Hence, two balls will meet after 2.5sec