Question

if a boy travel to A to B 20 cmand return to B to C 10 cm what will be the distance of displacement​

Answer 1

Answer:

the change in displacement will be 10 cm.

HOW ?

=> sol.

➡️ distance from A to B is 20 cm.

➡️ further, he returns to C on walking 10 cm.

➡️ C will lie in between A and B.

we know , displacement is the shortest path !!

therefore, change in displacement = (20-10) cm

= 10 cm.

for more information, refer to the attachment.

Explanation:

hope it helps ✔✔

Answer 2

Answer:

Given,

f = focal length = -10 cm (concave mirror)

u = Object distance = -20 cm

1/f = 1/v + 1/u where v= Image distance

1/v = 1/f - 1/u

= (1/-10) - (1/-20)

= (1/-10) + (1/20)

= (-2+1)/20

= -1/20

v = -20

Given,

h1 = Object size = 10cm

h2 = Image size = ?

M(magnification)= h1/h2 = -(v/u) (concave mirror)

= -(-20/20)

= 1

h2 = 1*h1 = 1*10 = 10 cm